[{"data":1,"prerenderedAt":2703},["ShallowReactive",2],{"doc-\u002Freference\u002Fpython-filter-function-explained":3},{"id":4,"title":5,"body":6,"description":2696,"extension":2697,"meta":2698,"navigation":272,"path":2699,"seo":2700,"stem":2701,"__hash__":2702},"content\u002Freference\u002Fpython-filter-function-explained.md","Python filter() Function Explained",{"type":7,"value":8,"toc":2653},"minimark",[9,19,25,28,38,54,59,191,199,206,211,214,232,235,319,322,341,348,352,355,376,381,384,397,402,405,408,425,428,509,511,529,538,542,551,554,569,571,663,665,721,724,728,731,810,812,834,837,846,852,855,965,967,992,995,1002,1008,1013,1016,1027,1142,1144,1166,1176,1184,1190,1210,1217,1220,1241,1243,1336,1338,1367,1370,1376,1382,1385,1396,1398,1487,1489,1509,1516,1628,1630,1650,1653,1739,1741,1761,1768,1772,1777,1784,1787,1844,1847,1850,1911,1920,1923,1926,1954,1957,2020,2022,2039,2043,2046,2124,2126,2146,2149,2226,2230,2233,2236,2245,2251,2254,2306,2315,2327,2332,2393,2395,2412,2416,2479,2481,2507,2516,2520,2527,2533,2540,2548,2555,2558,2566,2577,2584,2590,2593,2610,2617,2621,2649],[10,11,13,14,18],"h1",{"id":12},"python-filter-function-explained","Python ",[15,16,17],"code",{},"filter()"," Function Explained",[20,21,22,24],"p",{},[15,23,17],{}," is used to keep only the items that pass a test.",[20,26,27],{},"It takes:",[29,30,31,35],"ul",{},[32,33,34],"li",{},"a function that checks each item",[32,36,37],{},"an iterable such as a list, tuple, or string",[20,39,40,41,45,46,49,50,53],{},"The result is ",[42,43,44],"strong",{},"not a list"," in Python 3. It returns a ",[15,47,48],{},"filter"," object, so beginners often convert it with ",[15,51,52],{},"list()"," to see the values.",[55,56,58],"h2",{"id":57},"quick-example","Quick example",[60,61,66],"pre",{"className":62,"code":63,"language":64,"meta":65,"style":65},"language-python shiki shiki-themes material-theme-lighter github-light github-dark","numbers = [1, 2, 3, 4, 5, 6]\nresult = filter(lambda x: x % 2 == 0, numbers)\nprint(list(result))  # [2, 4, 6]\n","python","",[15,67,68,118,167],{"__ignoreMap":65},[69,70,73,77,81,85,89,92,95,97,100,102,105,107,110,112,115],"span",{"class":71,"line":72},"line",1,[69,74,76],{"class":75},"su5hD","numbers ",[69,78,80],{"class":79},"smGrS","=",[69,82,84],{"class":83},"sP7_E"," [",[69,86,88],{"class":87},"srdBf","1",[69,90,91],{"class":83},",",[69,93,94],{"class":87}," 2",[69,96,91],{"class":83},[69,98,99],{"class":87}," 3",[69,101,91],{"class":83},[69,103,104],{"class":87}," 4",[69,106,91],{"class":83},[69,108,109],{"class":87}," 5",[69,111,91],{"class":83},[69,113,114],{"class":87}," 6",[69,116,117],{"class":83},"]\n",[69,119,121,124,126,130,133,137,141,144,148,151,153,156,159,161,164],{"class":71,"line":120},2,[69,122,123],{"class":75},"result ",[69,125,80],{"class":79},[69,127,129],{"class":128},"sptTA"," filter",[69,131,132],{"class":83},"(",[69,134,136],{"class":135},"sbsja","lambda",[69,138,140],{"class":139},"sFwrP"," x",[69,142,143],{"class":83},":",[69,145,147],{"class":146},"slqww"," x ",[69,149,150],{"class":79},"%",[69,152,94],{"class":87},[69,154,155],{"class":79}," ==",[69,157,158],{"class":87}," 0",[69,160,91],{"class":83},[69,162,163],{"class":146}," numbers",[69,165,166],{"class":83},")\n",[69,168,170,173,175,179,181,184,187],{"class":71,"line":169},3,[69,171,172],{"class":128},"print",[69,174,132],{"class":83},[69,176,178],{"class":177},"sZMiF","list",[69,180,132],{"class":83},[69,182,183],{"class":146},"result",[69,185,186],{"class":83},"))",[69,188,190],{"class":189},"sutJx","  # [2, 4, 6]\n",[20,192,193,195,196,198],{},[15,194,17],{}," returns a filter object, so beginners often wrap it with ",[15,197,52],{}," to see the results.",[55,200,202,203,205],{"id":201},"what-filter-does","What ",[15,204,17],{}," does",[20,207,208,210],{},[15,209,17],{}," keeps items that pass a test.",[20,212,213],{},"That means:",[29,215,216,219,226],{},[32,217,218],{},"each item is checked one at a time",[32,220,221,222,225],{},"if the test returns ",[15,223,224],{},"True",", the item is kept",[32,227,221,228,231],{},[15,229,230],{},"False",", the item is removed",[20,233,234],{},"Example:",[60,236,238],{"className":62,"code":237,"language":64,"meta":65,"style":65},"numbers = [1, 2, 3, 4, 5]\n\nresult = filter(lambda x: x > 3, numbers)\nprint(list(result))\n",[15,239,240,268,274,303],{"__ignoreMap":65},[69,241,242,244,246,248,250,252,254,256,258,260,262,264,266],{"class":71,"line":72},[69,243,76],{"class":75},[69,245,80],{"class":79},[69,247,84],{"class":83},[69,249,88],{"class":87},[69,251,91],{"class":83},[69,253,94],{"class":87},[69,255,91],{"class":83},[69,257,99],{"class":87},[69,259,91],{"class":83},[69,261,104],{"class":87},[69,263,91],{"class":83},[69,265,109],{"class":87},[69,267,117],{"class":83},[69,269,270],{"class":71,"line":120},[69,271,273],{"emptyLinePlaceholder":272},true,"\n",[69,275,276,278,280,282,284,286,288,290,292,295,297,299,301],{"class":71,"line":169},[69,277,123],{"class":75},[69,279,80],{"class":79},[69,281,129],{"class":128},[69,283,132],{"class":83},[69,285,136],{"class":135},[69,287,140],{"class":139},[69,289,143],{"class":83},[69,291,147],{"class":146},[69,293,294],{"class":79},">",[69,296,99],{"class":87},[69,298,91],{"class":83},[69,300,163],{"class":146},[69,302,166],{"class":83},[69,304,306,308,310,312,314,316],{"class":71,"line":305},4,[69,307,172],{"class":128},[69,309,132],{"class":83},[69,311,178],{"class":177},[69,313,132],{"class":83},[69,315,183],{"class":146},[69,317,318],{"class":83},"))\n",[20,320,321],{},"Output:",[60,323,325],{"className":62,"code":324,"language":64,"meta":65,"style":65},"[4, 5]\n",[15,326,327],{"__ignoreMap":65},[69,328,329,332,335,337,339],{"class":71,"line":72},[69,330,331],{"class":83},"[",[69,333,334],{"class":87},"4",[69,336,91],{"class":83},[69,338,109],{"class":87},[69,340,117],{"class":83},[20,342,343,344,347],{},"Here, only numbers greater than ",[15,345,346],{},"3"," are kept.",[55,349,351],{"id":350},"syntax-and-arguments","Syntax and arguments",[20,353,354],{},"The syntax is:",[60,356,358],{"className":62,"code":357,"language":64,"meta":65,"style":65},"filter(function, iterable)\n",[15,359,360],{"__ignoreMap":65},[69,361,362,364,366,369,371,374],{"class":71,"line":72},[69,363,48],{"class":128},[69,365,132],{"class":83},[69,367,368],{"class":146},"function",[69,370,91],{"class":83},[69,372,373],{"class":146}," iterable",[69,375,166],{"class":83},[377,378,379],"h3",{"id":368},[15,380,368],{},[20,382,383],{},"This is the test function.",[29,385,386,389],{},[32,387,388],{},"It receives one item at a time",[32,390,391,392,394,395],{},"It should return ",[15,393,224],{}," or ",[15,396,230],{},[377,398,400],{"id":399},"iterable",[15,401,399],{},[20,403,404],{},"This is the group of values to check.",[20,406,407],{},"It can be:",[29,409,410,413,416,419,422],{},[32,411,412],{},"a list",[32,414,415],{},"a tuple",[32,417,418],{},"a string",[32,420,421],{},"a set",[32,423,424],{},"another iterable object",[20,426,427],{},"Example with a tuple:",[60,429,431],{"className":62,"code":430,"language":64,"meta":65,"style":65},"numbers = (10, 15, 20, 25)\n\nresult = filter(lambda x: x >= 20, numbers)\nprint(list(result))\n",[15,432,433,462,466,495],{"__ignoreMap":65},[69,434,435,437,439,442,445,447,450,452,455,457,460],{"class":71,"line":72},[69,436,76],{"class":75},[69,438,80],{"class":79},[69,440,441],{"class":83}," (",[69,443,444],{"class":87},"10",[69,446,91],{"class":83},[69,448,449],{"class":87}," 15",[69,451,91],{"class":83},[69,453,454],{"class":87}," 20",[69,456,91],{"class":83},[69,458,459],{"class":87}," 25",[69,461,166],{"class":83},[69,463,464],{"class":71,"line":120},[69,465,273],{"emptyLinePlaceholder":272},[69,467,468,470,472,474,476,478,480,482,484,487,489,491,493],{"class":71,"line":169},[69,469,123],{"class":75},[69,471,80],{"class":79},[69,473,129],{"class":128},[69,475,132],{"class":83},[69,477,136],{"class":135},[69,479,140],{"class":139},[69,481,143],{"class":83},[69,483,147],{"class":146},[69,485,486],{"class":79},">=",[69,488,454],{"class":87},[69,490,91],{"class":83},[69,492,163],{"class":146},[69,494,166],{"class":83},[69,496,497,499,501,503,505,507],{"class":71,"line":305},[69,498,172],{"class":128},[69,500,132],{"class":83},[69,502,178],{"class":177},[69,504,132],{"class":83},[69,506,183],{"class":146},[69,508,318],{"class":83},[20,510,321],{},[60,512,514],{"className":62,"code":513,"language":64,"meta":65,"style":65},"[20, 25]\n",[15,515,516],{"__ignoreMap":65},[69,517,518,520,523,525,527],{"class":71,"line":72},[69,519,331],{"class":83},[69,521,522],{"class":87},"20",[69,524,91],{"class":83},[69,526,459],{"class":87},[69,528,117],{"class":83},[20,530,531,532,537],{},"If you are new to iterables, see ",[533,534,536],"a",{"href":535},"\u002Flearn\u002Fiterators-and-iterable-objects-explained\u002F","iterators and iterable objects explained",".",[55,539,541],{"id":540},"what-the-return-value-means","What the return value means",[20,543,544,545,547,548,537],{},"In Python 3, ",[15,546,17],{}," returns a ",[42,549,550],{},"filter object",[20,552,553],{},"This is an iterator-like object. You can:",[29,555,556,559,564],{},[32,557,558],{},"loop through it",[32,560,561,562],{},"convert it with ",[15,563,52],{},[32,565,561,566],{},[15,567,568],{},"tuple()",[20,570,234],{},[60,572,574],{"className":62,"code":573,"language":64,"meta":65,"style":65},"result = filter(lambda x: x > 2, [1, 2, 3, 4])\n\nprint(result)\nprint(type(result))\nprint(list(result))\n",[15,575,576,619,623,633,648],{"__ignoreMap":65},[69,577,578,580,582,584,586,588,590,592,594,596,598,600,602,604,606,608,610,612,614,616],{"class":71,"line":72},[69,579,123],{"class":75},[69,581,80],{"class":79},[69,583,129],{"class":128},[69,585,132],{"class":83},[69,587,136],{"class":135},[69,589,140],{"class":139},[69,591,143],{"class":83},[69,593,147],{"class":146},[69,595,294],{"class":79},[69,597,94],{"class":87},[69,599,91],{"class":83},[69,601,84],{"class":83},[69,603,88],{"class":87},[69,605,91],{"class":83},[69,607,94],{"class":87},[69,609,91],{"class":83},[69,611,99],{"class":87},[69,613,91],{"class":83},[69,615,104],{"class":87},[69,617,618],{"class":83},"])\n",[69,620,621],{"class":71,"line":120},[69,622,273],{"emptyLinePlaceholder":272},[69,624,625,627,629,631],{"class":71,"line":169},[69,626,172],{"class":128},[69,628,132],{"class":83},[69,630,183],{"class":146},[69,632,166],{"class":83},[69,634,635,637,639,642,644,646],{"class":71,"line":305},[69,636,172],{"class":128},[69,638,132],{"class":83},[69,640,641],{"class":177},"type",[69,643,132],{"class":83},[69,645,183],{"class":146},[69,647,318],{"class":83},[69,649,651,653,655,657,659,661],{"class":71,"line":650},5,[69,652,172],{"class":128},[69,654,132],{"class":83},[69,656,178],{"class":177},[69,658,132],{"class":83},[69,660,183],{"class":146},[69,662,318],{"class":83},[20,664,321],{},[60,666,668],{"className":62,"code":667,"language":64,"meta":65,"style":65},"\u003Cfilter object at ...>\n\u003Cclass 'filter'>\n[3, 4]\n",[15,669,670,690,709],{"__ignoreMap":65},[69,671,672,675,677,680,683,687],{"class":71,"line":72},[69,673,674],{"class":79},"\u003C",[69,676,48],{"class":128},[69,678,679],{"class":177}," object",[69,681,682],{"class":75}," at ",[69,684,686],{"class":685},"s_hVV","...",[69,688,689],{"class":79},">\n",[69,691,692,694,697,701,704,707],{"class":71,"line":120},[69,693,674],{"class":79},[69,695,696],{"class":135},"class",[69,698,700],{"class":699},"sjJ54"," '",[69,702,48],{"class":703},"s_sjI",[69,705,706],{"class":699},"'",[69,708,689],{"class":79},[69,710,711,713,715,717,719],{"class":71,"line":169},[69,712,331],{"class":83},[69,714,346],{"class":87},[69,716,91],{"class":83},[69,718,104],{"class":87},[69,720,117],{"class":83},[20,722,723],{},"If you print the filter object directly, you will not see the filtered items.",[377,725,727],{"id":726},"important-a-filter-object-is-consumed-as-you-use-it","Important: a filter object is consumed as you use it",[20,729,730],{},"Once you loop through it or convert it to a list, the items are used up.",[60,732,734],{"className":62,"code":733,"language":64,"meta":65,"style":65},"result = filter(lambda x: x > 2, [1, 2, 3, 4])\n\nprint(list(result))\nprint(list(result))\n",[15,735,736,778,782,796],{"__ignoreMap":65},[69,737,738,740,742,744,746,748,750,752,754,756,758,760,762,764,766,768,770,772,774,776],{"class":71,"line":72},[69,739,123],{"class":75},[69,741,80],{"class":79},[69,743,129],{"class":128},[69,745,132],{"class":83},[69,747,136],{"class":135},[69,749,140],{"class":139},[69,751,143],{"class":83},[69,753,147],{"class":146},[69,755,294],{"class":79},[69,757,94],{"class":87},[69,759,91],{"class":83},[69,761,84],{"class":83},[69,763,88],{"class":87},[69,765,91],{"class":83},[69,767,94],{"class":87},[69,769,91],{"class":83},[69,771,99],{"class":87},[69,773,91],{"class":83},[69,775,104],{"class":87},[69,777,618],{"class":83},[69,779,780],{"class":71,"line":120},[69,781,273],{"emptyLinePlaceholder":272},[69,783,784,786,788,790,792,794],{"class":71,"line":169},[69,785,172],{"class":128},[69,787,132],{"class":83},[69,789,178],{"class":177},[69,791,132],{"class":83},[69,793,183],{"class":146},[69,795,318],{"class":83},[69,797,798,800,802,804,806,808],{"class":71,"line":305},[69,799,172],{"class":128},[69,801,132],{"class":83},[69,803,178],{"class":177},[69,805,132],{"class":83},[69,807,183],{"class":146},[69,809,318],{"class":83},[20,811,321],{},[60,813,815],{"className":62,"code":814,"language":64,"meta":65,"style":65},"[3, 4]\n[]\n",[15,816,817,829],{"__ignoreMap":65},[69,818,819,821,823,825,827],{"class":71,"line":72},[69,820,331],{"class":83},[69,822,346],{"class":87},[69,824,91],{"class":83},[69,826,104],{"class":87},[69,828,117],{"class":83},[69,830,831],{"class":71,"line":120},[69,832,833],{"class":83},"[]\n",[20,835,836],{},"The second result is empty because the filter object was already consumed.",[55,838,840,841,843,844],{"id":839},"using-filter-with-lambda","Using ",[15,842,17],{}," with ",[15,845,136],{},[20,847,848,849,851],{},"A ",[15,850,136],{}," is a short anonymous function.",[20,853,854],{},"It is useful for simple filtering rules that fit on one line.",[60,856,858],{"className":62,"code":857,"language":64,"meta":65,"style":65},"words = [\"apple\", \"kiwi\", \"banana\", \"fig\"]\n\nresult = filter(lambda word: len(word) > 4, words)\nprint(list(result))\n",[15,859,860,907,911,951],{"__ignoreMap":65},[69,861,862,865,867,869,872,875,877,879,882,885,887,889,891,894,896,898,900,903,905],{"class":71,"line":72},[69,863,864],{"class":75},"words ",[69,866,80],{"class":79},[69,868,84],{"class":83},[69,870,871],{"class":699},"\"",[69,873,874],{"class":703},"apple",[69,876,871],{"class":699},[69,878,91],{"class":83},[69,880,881],{"class":699}," \"",[69,883,884],{"class":703},"kiwi",[69,886,871],{"class":699},[69,888,91],{"class":83},[69,890,881],{"class":699},[69,892,893],{"class":703},"banana",[69,895,871],{"class":699},[69,897,91],{"class":83},[69,899,881],{"class":699},[69,901,902],{"class":703},"fig",[69,904,871],{"class":699},[69,906,117],{"class":83},[69,908,909],{"class":71,"line":120},[69,910,273],{"emptyLinePlaceholder":272},[69,912,913,915,917,919,921,923,926,928,931,933,936,939,942,944,946,949],{"class":71,"line":169},[69,914,123],{"class":75},[69,916,80],{"class":79},[69,918,129],{"class":128},[69,920,132],{"class":83},[69,922,136],{"class":135},[69,924,925],{"class":139}," word",[69,927,143],{"class":83},[69,929,930],{"class":128}," len",[69,932,132],{"class":83},[69,934,935],{"class":146},"word",[69,937,938],{"class":83},")",[69,940,941],{"class":79}," >",[69,943,104],{"class":87},[69,945,91],{"class":83},[69,947,948],{"class":146}," words",[69,950,166],{"class":83},[69,952,953,955,957,959,961,963],{"class":71,"line":305},[69,954,172],{"class":128},[69,956,132],{"class":83},[69,958,178],{"class":177},[69,960,132],{"class":83},[69,962,183],{"class":146},[69,964,318],{"class":83},[20,966,321],{},[60,968,970],{"className":62,"code":969,"language":64,"meta":65,"style":65},"['apple', 'banana']\n",[15,971,972],{"__ignoreMap":65},[69,973,974,976,978,980,982,984,986,988,990],{"class":71,"line":72},[69,975,331],{"class":83},[69,977,706],{"class":699},[69,979,874],{"class":703},[69,981,706],{"class":699},[69,983,91],{"class":83},[69,985,700],{"class":699},[69,987,893],{"class":703},[69,989,706],{"class":699},[69,991,117],{"class":83},[20,993,994],{},"This keeps only words with more than 4 characters.",[20,996,997,998,537],{},"If you want to learn this syntax more clearly, see ",[533,999,1001],{"href":1000},"\u002Flearn\u002Flambda-functions-in-python-explained\u002F","lambda functions in Python explained",[55,1003,840,1005,1007],{"id":1004},"using-filter-with-a-named-function",[15,1006,17],{}," with a named function",[20,1009,1010,1011,537],{},"A named function is often easier to read than a complex ",[15,1012,136],{},[20,1014,1015],{},"This is especially helpful when:",[29,1017,1018,1021,1024],{},[32,1019,1020],{},"the logic needs a clear name",[32,1022,1023],{},"the rule is more than a very short check",[32,1025,1026],{},"you want beginner-friendly code",[60,1028,1030],{"className":62,"code":1029,"language":64,"meta":65,"style":65},"def is_even(number):\n    return number % 2 == 0\n\nnumbers = [1, 2, 3, 4, 5, 6]\nresult = filter(is_even, numbers)\n\nprint(list(result))\n",[15,1031,1032,1049,1067,1071,1103,1122,1127],{"__ignoreMap":65},[69,1033,1034,1037,1041,1043,1046],{"class":71,"line":72},[69,1035,1036],{"class":135},"def",[69,1038,1040],{"class":1039},"sGLFI"," is_even",[69,1042,132],{"class":83},[69,1044,1045],{"class":139},"number",[69,1047,1048],{"class":83},"):\n",[69,1050,1051,1055,1058,1060,1062,1064],{"class":71,"line":120},[69,1052,1054],{"class":1053},"sVHd0","    return",[69,1056,1057],{"class":75}," number ",[69,1059,150],{"class":79},[69,1061,94],{"class":87},[69,1063,155],{"class":79},[69,1065,1066],{"class":87}," 0\n",[69,1068,1069],{"class":71,"line":169},[69,1070,273],{"emptyLinePlaceholder":272},[69,1072,1073,1075,1077,1079,1081,1083,1085,1087,1089,1091,1093,1095,1097,1099,1101],{"class":71,"line":305},[69,1074,76],{"class":75},[69,1076,80],{"class":79},[69,1078,84],{"class":83},[69,1080,88],{"class":87},[69,1082,91],{"class":83},[69,1084,94],{"class":87},[69,1086,91],{"class":83},[69,1088,99],{"class":87},[69,1090,91],{"class":83},[69,1092,104],{"class":87},[69,1094,91],{"class":83},[69,1096,109],{"class":87},[69,1098,91],{"class":83},[69,1100,114],{"class":87},[69,1102,117],{"class":83},[69,1104,1105,1107,1109,1111,1113,1116,1118,1120],{"class":71,"line":650},[69,1106,123],{"class":75},[69,1108,80],{"class":79},[69,1110,129],{"class":128},[69,1112,132],{"class":83},[69,1114,1115],{"class":146},"is_even",[69,1117,91],{"class":83},[69,1119,163],{"class":146},[69,1121,166],{"class":83},[69,1123,1125],{"class":71,"line":1124},6,[69,1126,273],{"emptyLinePlaceholder":272},[69,1128,1130,1132,1134,1136,1138,1140],{"class":71,"line":1129},7,[69,1131,172],{"class":128},[69,1133,132],{"class":83},[69,1135,178],{"class":177},[69,1137,132],{"class":83},[69,1139,183],{"class":146},[69,1141,318],{"class":83},[20,1143,321],{},[60,1145,1147],{"className":62,"code":1146,"language":64,"meta":65,"style":65},"[2, 4, 6]\n",[15,1148,1149],{"__ignoreMap":65},[69,1150,1151,1153,1156,1158,1160,1162,1164],{"class":71,"line":72},[69,1152,331],{"class":83},[69,1154,1155],{"class":87},"2",[69,1157,91],{"class":83},[69,1159,104],{"class":87},[69,1161,91],{"class":83},[69,1163,114],{"class":87},[69,1165,117],{"class":83},[20,1167,1168,1169,1172,1173,1175],{},"Here, ",[15,1170,1171],{},"is_even()"," returns ",[15,1174,224],{}," for even numbers, so those numbers are kept.",[55,1177,840,1179,843,1182],{"id":1178},"using-none-with-filter",[15,1180,1181],{},"None",[15,1183,17],{},[20,1185,1186,1187,1189],{},"You can pass ",[15,1188,1181],{}," as the first argument:",[60,1191,1193],{"className":62,"code":1192,"language":64,"meta":65,"style":65},"filter(None, iterable)\n",[15,1194,1195],{"__ignoreMap":65},[69,1196,1197,1199,1201,1204,1206,1208],{"class":71,"line":72},[69,1198,48],{"class":128},[69,1200,132],{"class":83},[69,1202,1181],{"class":1203},"s39Yj",[69,1205,91],{"class":83},[69,1207,373],{"class":146},[69,1209,166],{"class":83},[20,1211,1212,1213,1216],{},"In this case, Python removes ",[42,1214,1215],{},"falsy"," values.",[20,1218,1219],{},"Falsy values include:",[29,1221,1222,1227,1233,1237],{},[32,1223,1224],{},[15,1225,1226],{},"0",[32,1228,1229,1232],{},[15,1230,1231],{},"''"," (empty string)",[32,1234,1235],{},[15,1236,1181],{},[32,1238,1239],{},[15,1240,230],{},[20,1242,234],{},[60,1244,1246],{"className":62,"code":1245,"language":64,"meta":65,"style":65},"items = [0, 1, \"\", \"hello\", None, True, False, 5]\n\nresult = filter(None, items)\nprint(list(result))\n",[15,1247,1248,1299,1303,1322],{"__ignoreMap":65},[69,1249,1250,1253,1255,1257,1259,1261,1264,1266,1269,1271,1273,1276,1278,1280,1283,1285,1288,1290,1293,1295,1297],{"class":71,"line":72},[69,1251,1252],{"class":75},"items ",[69,1254,80],{"class":79},[69,1256,84],{"class":83},[69,1258,1226],{"class":87},[69,1260,91],{"class":83},[69,1262,1263],{"class":87}," 1",[69,1265,91],{"class":83},[69,1267,1268],{"class":699}," \"\"",[69,1270,91],{"class":83},[69,1272,881],{"class":699},[69,1274,1275],{"class":703},"hello",[69,1277,871],{"class":699},[69,1279,91],{"class":83},[69,1281,1282],{"class":1203}," None",[69,1284,91],{"class":83},[69,1286,1287],{"class":1203}," True",[69,1289,91],{"class":83},[69,1291,1292],{"class":1203}," False",[69,1294,91],{"class":83},[69,1296,109],{"class":87},[69,1298,117],{"class":83},[69,1300,1301],{"class":71,"line":120},[69,1302,273],{"emptyLinePlaceholder":272},[69,1304,1305,1307,1309,1311,1313,1315,1317,1320],{"class":71,"line":169},[69,1306,123],{"class":75},[69,1308,80],{"class":79},[69,1310,129],{"class":128},[69,1312,132],{"class":83},[69,1314,1181],{"class":1203},[69,1316,91],{"class":83},[69,1318,1319],{"class":146}," items",[69,1321,166],{"class":83},[69,1323,1324,1326,1328,1330,1332,1334],{"class":71,"line":305},[69,1325,172],{"class":128},[69,1327,132],{"class":83},[69,1329,178],{"class":177},[69,1331,132],{"class":83},[69,1333,183],{"class":146},[69,1335,318],{"class":83},[20,1337,321],{},[60,1339,1341],{"className":62,"code":1340,"language":64,"meta":65,"style":65},"[1, 'hello', True, 5]\n",[15,1342,1343],{"__ignoreMap":65},[69,1344,1345,1347,1349,1351,1353,1355,1357,1359,1361,1363,1365],{"class":71,"line":72},[69,1346,331],{"class":83},[69,1348,88],{"class":87},[69,1350,91],{"class":83},[69,1352,700],{"class":699},[69,1354,1275],{"class":703},[69,1356,706],{"class":699},[69,1358,91],{"class":83},[69,1360,1287],{"class":1203},[69,1362,91],{"class":83},[69,1364,109],{"class":87},[69,1366,117],{"class":83},[20,1368,1369],{},"This is useful when you want to remove empty or false-like values from data.",[55,1371,1373,1374],{"id":1372},"when-to-use-filter","When to use ",[15,1375,17],{},[20,1377,1378,1379,1381],{},"Use ",[15,1380,17],{}," when you want to keep only matching items.",[20,1383,1384],{},"It works well for:",[29,1386,1387,1390,1393],{},[32,1388,1389],{},"simple filtering rules",[32,1391,1392],{},"quick data cleaning",[32,1394,1395],{},"cases where a function already exists for the test",[20,1397,234],{},[60,1399,1401],{"className":62,"code":1400,"language":64,"meta":65,"style":65},"numbers = [1, 2, 3, 4, 5, 6]\nevens = filter(lambda x: x % 2 == 0, numbers)\n\nprint(list(evens))\n",[15,1402,1403,1435,1468,1472],{"__ignoreMap":65},[69,1404,1405,1407,1409,1411,1413,1415,1417,1419,1421,1423,1425,1427,1429,1431,1433],{"class":71,"line":72},[69,1406,76],{"class":75},[69,1408,80],{"class":79},[69,1410,84],{"class":83},[69,1412,88],{"class":87},[69,1414,91],{"class":83},[69,1416,94],{"class":87},[69,1418,91],{"class":83},[69,1420,99],{"class":87},[69,1422,91],{"class":83},[69,1424,104],{"class":87},[69,1426,91],{"class":83},[69,1428,109],{"class":87},[69,1430,91],{"class":83},[69,1432,114],{"class":87},[69,1434,117],{"class":83},[69,1436,1437,1440,1442,1444,1446,1448,1450,1452,1454,1456,1458,1460,1462,1464,1466],{"class":71,"line":120},[69,1438,1439],{"class":75},"evens ",[69,1441,80],{"class":79},[69,1443,129],{"class":128},[69,1445,132],{"class":83},[69,1447,136],{"class":135},[69,1449,140],{"class":139},[69,1451,143],{"class":83},[69,1453,147],{"class":146},[69,1455,150],{"class":79},[69,1457,94],{"class":87},[69,1459,155],{"class":79},[69,1461,158],{"class":87},[69,1463,91],{"class":83},[69,1465,163],{"class":146},[69,1467,166],{"class":83},[69,1469,1470],{"class":71,"line":169},[69,1471,273],{"emptyLinePlaceholder":272},[69,1473,1474,1476,1478,1480,1482,1485],{"class":71,"line":305},[69,1475,172],{"class":128},[69,1477,132],{"class":83},[69,1479,178],{"class":177},[69,1481,132],{"class":83},[69,1483,1484],{"class":146},"evens",[69,1486,318],{"class":83},[20,1488,321],{},[60,1490,1491],{"className":62,"code":1146,"language":64,"meta":65,"style":65},[15,1492,1493],{"__ignoreMap":65},[69,1494,1495,1497,1499,1501,1503,1505,1507],{"class":71,"line":72},[69,1496,331],{"class":83},[69,1498,1155],{"class":87},[69,1500,91],{"class":83},[69,1502,104],{"class":87},[69,1504,91],{"class":83},[69,1506,114],{"class":87},[69,1508,117],{"class":83},[20,1510,1511,1512,1515],{},"For beginners, though, a ",[15,1513,1514],{},"for"," loop may be easier to understand.",[60,1517,1519],{"className":62,"code":1518,"language":64,"meta":65,"style":65},"numbers = [1, 2, 3, 4, 5, 6]\nevens = []\n\nfor number in numbers:\n    if number % 2 == 0:\n        evens.append(number)\n\nprint(evens)\n",[15,1520,1521,1553,1562,1566,1580,1597,1613,1617],{"__ignoreMap":65},[69,1522,1523,1525,1527,1529,1531,1533,1535,1537,1539,1541,1543,1545,1547,1549,1551],{"class":71,"line":72},[69,1524,76],{"class":75},[69,1526,80],{"class":79},[69,1528,84],{"class":83},[69,1530,88],{"class":87},[69,1532,91],{"class":83},[69,1534,94],{"class":87},[69,1536,91],{"class":83},[69,1538,99],{"class":87},[69,1540,91],{"class":83},[69,1542,104],{"class":87},[69,1544,91],{"class":83},[69,1546,109],{"class":87},[69,1548,91],{"class":83},[69,1550,114],{"class":87},[69,1552,117],{"class":83},[69,1554,1555,1557,1559],{"class":71,"line":120},[69,1556,1439],{"class":75},[69,1558,80],{"class":79},[69,1560,1561],{"class":83}," []\n",[69,1563,1564],{"class":71,"line":169},[69,1565,273],{"emptyLinePlaceholder":272},[69,1567,1568,1570,1572,1575,1577],{"class":71,"line":305},[69,1569,1514],{"class":1053},[69,1571,1057],{"class":75},[69,1573,1574],{"class":1053},"in",[69,1576,163],{"class":75},[69,1578,1579],{"class":83},":\n",[69,1581,1582,1585,1587,1589,1591,1593,1595],{"class":71,"line":650},[69,1583,1584],{"class":1053},"    if",[69,1586,1057],{"class":75},[69,1588,150],{"class":79},[69,1590,94],{"class":87},[69,1592,155],{"class":79},[69,1594,158],{"class":87},[69,1596,1579],{"class":83},[69,1598,1599,1602,1604,1607,1609,1611],{"class":71,"line":1124},[69,1600,1601],{"class":75},"        evens",[69,1603,537],{"class":83},[69,1605,1606],{"class":146},"append",[69,1608,132],{"class":83},[69,1610,1045],{"class":146},[69,1612,166],{"class":83},[69,1614,1615],{"class":71,"line":1129},[69,1616,273],{"emptyLinePlaceholder":272},[69,1618,1620,1622,1624,1626],{"class":71,"line":1619},8,[69,1621,172],{"class":128},[69,1623,132],{"class":83},[69,1625,1484],{"class":146},[69,1627,166],{"class":83},[20,1629,321],{},[60,1631,1632],{"className":62,"code":1146,"language":64,"meta":65,"style":65},[15,1633,1634],{"__ignoreMap":65},[69,1635,1636,1638,1640,1642,1644,1646,1648],{"class":71,"line":72},[69,1637,331],{"class":83},[69,1639,1155],{"class":87},[69,1641,91],{"class":83},[69,1643,104],{"class":87},[69,1645,91],{"class":83},[69,1647,114],{"class":87},[69,1649,117],{"class":83},[20,1651,1652],{},"A list comprehension is also a common alternative:",[60,1654,1656],{"className":62,"code":1655,"language":64,"meta":65,"style":65},"numbers = [1, 2, 3, 4, 5, 6]\nevens = [number for number in numbers if number % 2 == 0]\n\nprint(evens)\n",[15,1657,1658,1690,1725,1729],{"__ignoreMap":65},[69,1659,1660,1662,1664,1666,1668,1670,1672,1674,1676,1678,1680,1682,1684,1686,1688],{"class":71,"line":72},[69,1661,76],{"class":75},[69,1663,80],{"class":79},[69,1665,84],{"class":83},[69,1667,88],{"class":87},[69,1669,91],{"class":83},[69,1671,94],{"class":87},[69,1673,91],{"class":83},[69,1675,99],{"class":87},[69,1677,91],{"class":83},[69,1679,104],{"class":87},[69,1681,91],{"class":83},[69,1683,109],{"class":87},[69,1685,91],{"class":83},[69,1687,114],{"class":87},[69,1689,117],{"class":83},[69,1691,1692,1694,1696,1698,1701,1703,1705,1707,1710,1713,1715,1717,1719,1721,1723],{"class":71,"line":120},[69,1693,1439],{"class":75},[69,1695,80],{"class":79},[69,1697,84],{"class":83},[69,1699,1700],{"class":75},"number ",[69,1702,1514],{"class":1053},[69,1704,1057],{"class":75},[69,1706,1574],{"class":1053},[69,1708,1709],{"class":75}," numbers ",[69,1711,1712],{"class":1053},"if",[69,1714,1057],{"class":75},[69,1716,150],{"class":79},[69,1718,94],{"class":87},[69,1720,155],{"class":79},[69,1722,158],{"class":87},[69,1724,117],{"class":83},[69,1726,1727],{"class":71,"line":169},[69,1728,273],{"emptyLinePlaceholder":272},[69,1730,1731,1733,1735,1737],{"class":71,"line":305},[69,1732,172],{"class":128},[69,1734,132],{"class":83},[69,1736,1484],{"class":146},[69,1738,166],{"class":83},[20,1740,321],{},[60,1742,1743],{"className":62,"code":1146,"language":64,"meta":65,"style":65},[15,1744,1745],{"__ignoreMap":65},[69,1746,1747,1749,1751,1753,1755,1757,1759],{"class":71,"line":72},[69,1748,331],{"class":83},[69,1750,1155],{"class":87},[69,1752,91],{"class":83},[69,1754,104],{"class":87},[69,1756,91],{"class":83},[69,1758,114],{"class":87},[69,1760,117],{"class":83},[20,1762,1763,1764,537],{},"If you want another common filtering style, see ",[533,1765,1767],{"href":1766},"\u002Flearn\u002Flist-comprehensions-in-python-explained\u002F","list comprehensions in Python explained",[55,1769,1771],{"id":1770},"common-mistakes","Common mistakes",[20,1773,1774,1775,537],{},"Here are some common problems beginners run into with ",[15,1776,17],{},[377,1778,1780,1781,1783],{"id":1779},"expecting-filter-to-return-a-list","Expecting ",[15,1782,17],{}," to return a list",[20,1785,1786],{},"This is the most common mistake.",[60,1788,1790],{"className":62,"code":1789,"language":64,"meta":65,"style":65},"result = filter(lambda x: x > 2, [1, 2, 3, 4])\nprint(result)\n",[15,1791,1792,1834],{"__ignoreMap":65},[69,1793,1794,1796,1798,1800,1802,1804,1806,1808,1810,1812,1814,1816,1818,1820,1822,1824,1826,1828,1830,1832],{"class":71,"line":72},[69,1795,123],{"class":75},[69,1797,80],{"class":79},[69,1799,129],{"class":128},[69,1801,132],{"class":83},[69,1803,136],{"class":135},[69,1805,140],{"class":139},[69,1807,143],{"class":83},[69,1809,147],{"class":146},[69,1811,294],{"class":79},[69,1813,94],{"class":87},[69,1815,91],{"class":83},[69,1817,84],{"class":83},[69,1819,88],{"class":87},[69,1821,91],{"class":83},[69,1823,94],{"class":87},[69,1825,91],{"class":83},[69,1827,99],{"class":87},[69,1829,91],{"class":83},[69,1831,104],{"class":87},[69,1833,618],{"class":83},[69,1835,1836,1838,1840,1842],{"class":71,"line":120},[69,1837,172],{"class":128},[69,1839,132],{"class":83},[69,1841,183],{"class":146},[69,1843,166],{"class":83},[20,1845,1846],{},"This prints a filter object, not the values.",[20,1848,1849],{},"Fix:",[60,1851,1853],{"className":62,"code":1852,"language":64,"meta":65,"style":65},"result = filter(lambda x: x > 2, [1, 2, 3, 4])\nprint(list(result))\n",[15,1854,1855,1897],{"__ignoreMap":65},[69,1856,1857,1859,1861,1863,1865,1867,1869,1871,1873,1875,1877,1879,1881,1883,1885,1887,1889,1891,1893,1895],{"class":71,"line":72},[69,1858,123],{"class":75},[69,1860,80],{"class":79},[69,1862,129],{"class":128},[69,1864,132],{"class":83},[69,1866,136],{"class":135},[69,1868,140],{"class":139},[69,1870,143],{"class":83},[69,1872,147],{"class":146},[69,1874,294],{"class":79},[69,1876,94],{"class":87},[69,1878,91],{"class":83},[69,1880,84],{"class":83},[69,1882,88],{"class":87},[69,1884,91],{"class":83},[69,1886,94],{"class":87},[69,1888,91],{"class":83},[69,1890,99],{"class":87},[69,1892,91],{"class":83},[69,1894,104],{"class":87},[69,1896,618],{"class":83},[69,1898,1899,1901,1903,1905,1907,1909],{"class":71,"line":120},[69,1900,172],{"class":128},[69,1902,132],{"class":83},[69,1904,178],{"class":177},[69,1906,132],{"class":83},[69,1908,183],{"class":146},[69,1910,318],{"class":83},[377,1912,1914,1915,394,1917,1919],{"id":1913},"using-a-test-function-that-does-not-return-true-or-false-clearly","Using a test function that does not return ",[15,1916,224],{},[15,1918,230],{}," clearly",[20,1921,1922],{},"Your function should make it obvious whether an item should stay.",[20,1924,1925],{},"Good example:",[60,1927,1929],{"className":62,"code":1928,"language":64,"meta":65,"style":65},"def is_positive(number):\n    return number > 0\n",[15,1930,1931,1944],{"__ignoreMap":65},[69,1932,1933,1935,1938,1940,1942],{"class":71,"line":72},[69,1934,1036],{"class":135},[69,1936,1937],{"class":1039}," is_positive",[69,1939,132],{"class":83},[69,1941,1045],{"class":139},[69,1943,1048],{"class":83},[69,1945,1946,1948,1950,1952],{"class":71,"line":120},[69,1947,1054],{"class":1053},[69,1949,1057],{"class":75},[69,1951,294],{"class":79},[69,1953,1066],{"class":87},[20,1955,1956],{},"Then use it with:",[60,1958,1960],{"className":62,"code":1959,"language":64,"meta":65,"style":65},"numbers = [-2, -1, 0, 1, 2]\nprint(list(filter(is_positive, numbers)))\n",[15,1961,1962,1996],{"__ignoreMap":65},[69,1963,1964,1966,1968,1970,1973,1975,1977,1980,1982,1984,1986,1988,1990,1992,1994],{"class":71,"line":72},[69,1965,76],{"class":75},[69,1967,80],{"class":79},[69,1969,84],{"class":83},[69,1971,1972],{"class":79},"-",[69,1974,1155],{"class":87},[69,1976,91],{"class":83},[69,1978,1979],{"class":79}," -",[69,1981,88],{"class":87},[69,1983,91],{"class":83},[69,1985,158],{"class":87},[69,1987,91],{"class":83},[69,1989,1263],{"class":87},[69,1991,91],{"class":83},[69,1993,94],{"class":87},[69,1995,117],{"class":83},[69,1997,1998,2000,2002,2004,2006,2008,2010,2013,2015,2017],{"class":71,"line":120},[69,1999,172],{"class":128},[69,2001,132],{"class":83},[69,2003,178],{"class":177},[69,2005,132],{"class":83},[69,2007,48],{"class":128},[69,2009,132],{"class":83},[69,2011,2012],{"class":146},"is_positive",[69,2014,91],{"class":83},[69,2016,163],{"class":146},[69,2018,2019],{"class":83},")))\n",[20,2021,321],{},[60,2023,2025],{"className":62,"code":2024,"language":64,"meta":65,"style":65},"[1, 2]\n",[15,2026,2027],{"__ignoreMap":65},[69,2028,2029,2031,2033,2035,2037],{"class":71,"line":72},[69,2030,331],{"class":83},[69,2032,88],{"class":87},[69,2034,91],{"class":83},[69,2036,94],{"class":87},[69,2038,117],{"class":83},[377,2040,2042],{"id":2041},"trying-to-reuse-the-same-filter-object-after-it-has-been-consumed","Trying to reuse the same filter object after it has been consumed",[20,2044,2045],{},"A filter object is not stored like a list.",[60,2047,2048],{"className":62,"code":733,"language":64,"meta":65,"style":65},[15,2049,2050,2092,2096,2110],{"__ignoreMap":65},[69,2051,2052,2054,2056,2058,2060,2062,2064,2066,2068,2070,2072,2074,2076,2078,2080,2082,2084,2086,2088,2090],{"class":71,"line":72},[69,2053,123],{"class":75},[69,2055,80],{"class":79},[69,2057,129],{"class":128},[69,2059,132],{"class":83},[69,2061,136],{"class":135},[69,2063,140],{"class":139},[69,2065,143],{"class":83},[69,2067,147],{"class":146},[69,2069,294],{"class":79},[69,2071,94],{"class":87},[69,2073,91],{"class":83},[69,2075,84],{"class":83},[69,2077,88],{"class":87},[69,2079,91],{"class":83},[69,2081,94],{"class":87},[69,2083,91],{"class":83},[69,2085,99],{"class":87},[69,2087,91],{"class":83},[69,2089,104],{"class":87},[69,2091,618],{"class":83},[69,2093,2094],{"class":71,"line":120},[69,2095,273],{"emptyLinePlaceholder":272},[69,2097,2098,2100,2102,2104,2106,2108],{"class":71,"line":169},[69,2099,172],{"class":128},[69,2101,132],{"class":83},[69,2103,178],{"class":177},[69,2105,132],{"class":83},[69,2107,183],{"class":146},[69,2109,318],{"class":83},[69,2111,2112,2114,2116,2118,2120,2122],{"class":71,"line":305},[69,2113,172],{"class":128},[69,2115,132],{"class":83},[69,2117,178],{"class":177},[69,2119,132],{"class":83},[69,2121,183],{"class":146},[69,2123,318],{"class":83},[20,2125,321],{},[60,2127,2128],{"className":62,"code":814,"language":64,"meta":65,"style":65},[15,2129,2130,2142],{"__ignoreMap":65},[69,2131,2132,2134,2136,2138,2140],{"class":71,"line":72},[69,2133,331],{"class":83},[69,2135,346],{"class":87},[69,2137,91],{"class":83},[69,2139,104],{"class":87},[69,2141,117],{"class":83},[69,2143,2144],{"class":71,"line":120},[69,2145,833],{"class":83},[20,2147,2148],{},"If you need to use the values again, convert once and save them:",[60,2150,2152],{"className":62,"code":2151,"language":64,"meta":65,"style":65},"result = list(filter(lambda x: x > 2, [1, 2, 3, 4]))\n\nprint(result)\nprint(result)\n",[15,2153,2154,2202,2206,2216],{"__ignoreMap":65},[69,2155,2156,2158,2160,2163,2165,2167,2169,2171,2173,2175,2177,2179,2181,2183,2185,2187,2189,2191,2193,2195,2197,2199],{"class":71,"line":72},[69,2157,123],{"class":75},[69,2159,80],{"class":79},[69,2161,2162],{"class":177}," list",[69,2164,132],{"class":83},[69,2166,48],{"class":128},[69,2168,132],{"class":83},[69,2170,136],{"class":135},[69,2172,140],{"class":139},[69,2174,143],{"class":83},[69,2176,147],{"class":146},[69,2178,294],{"class":79},[69,2180,94],{"class":87},[69,2182,91],{"class":83},[69,2184,84],{"class":83},[69,2186,88],{"class":87},[69,2188,91],{"class":83},[69,2190,94],{"class":87},[69,2192,91],{"class":83},[69,2194,99],{"class":87},[69,2196,91],{"class":83},[69,2198,104],{"class":87},[69,2200,2201],{"class":83},"]))\n",[69,2203,2204],{"class":71,"line":120},[69,2205,273],{"emptyLinePlaceholder":272},[69,2207,2208,2210,2212,2214],{"class":71,"line":169},[69,2209,172],{"class":128},[69,2211,132],{"class":83},[69,2213,183],{"class":146},[69,2215,166],{"class":83},[69,2217,2218,2220,2222,2224],{"class":71,"line":305},[69,2219,172],{"class":128},[69,2221,132],{"class":83},[69,2223,183],{"class":146},[69,2225,166],{"class":83},[377,2227,2229],{"id":2228},"passing-a-non-iterable-as-the-second-argument","Passing a non-iterable as the second argument",[20,2231,2232],{},"The second argument must be something you can loop over.",[20,2234,2235],{},"Wrong:",[60,2237,2239],{"className":62,"code":2238,"language":64,"meta":65,"style":65},"# filter(lambda x: x > 2, 10)\n",[15,2240,2241],{"__ignoreMap":65},[69,2242,2243],{"class":71,"line":72},[69,2244,2238],{"class":189},[20,2246,2247,2248,2250],{},"This causes an error because ",[15,2249,444],{}," is not iterable.",[20,2252,2253],{},"Correct:",[60,2255,2257],{"className":62,"code":2256,"language":64,"meta":65,"style":65},"print(list(filter(lambda x: x > 2, [1, 2, 3, 4])))\n",[15,2258,2259],{"__ignoreMap":65},[69,2260,2261,2263,2265,2267,2269,2271,2273,2275,2277,2279,2281,2283,2285,2287,2289,2291,2293,2295,2297,2299,2301,2303],{"class":71,"line":72},[69,2262,172],{"class":128},[69,2264,132],{"class":83},[69,2266,178],{"class":177},[69,2268,132],{"class":83},[69,2270,48],{"class":128},[69,2272,132],{"class":83},[69,2274,136],{"class":135},[69,2276,140],{"class":139},[69,2278,143],{"class":83},[69,2280,147],{"class":146},[69,2282,294],{"class":79},[69,2284,94],{"class":87},[69,2286,91],{"class":83},[69,2288,84],{"class":83},[69,2290,88],{"class":87},[69,2292,91],{"class":83},[69,2294,94],{"class":87},[69,2296,91],{"class":83},[69,2298,99],{"class":87},[69,2300,91],{"class":83},[69,2302,104],{"class":87},[69,2304,2305],{"class":83},"])))\n",[377,2307,2309,2310,843,2312],{"id":2308},"confusing-filter-with-map","Confusing ",[15,2311,17],{},[15,2313,2314],{},"map()",[29,2316,2317,2322],{},[32,2318,2319,2321],{},[15,2320,17],{}," keeps or removes items",[32,2323,2324,2326],{},[15,2325,2314],{}," changes each item into a new value",[20,2328,2329,2330,143],{},"Example of ",[15,2331,17],{},[60,2333,2335],{"className":62,"code":2334,"language":64,"meta":65,"style":65},"numbers = [1, 2, 3, 4]\nprint(list(filter(lambda x: x > 2, numbers)))\n",[15,2336,2337,2361],{"__ignoreMap":65},[69,2338,2339,2341,2343,2345,2347,2349,2351,2353,2355,2357,2359],{"class":71,"line":72},[69,2340,76],{"class":75},[69,2342,80],{"class":79},[69,2344,84],{"class":83},[69,2346,88],{"class":87},[69,2348,91],{"class":83},[69,2350,94],{"class":87},[69,2352,91],{"class":83},[69,2354,99],{"class":87},[69,2356,91],{"class":83},[69,2358,104],{"class":87},[69,2360,117],{"class":83},[69,2362,2363,2365,2367,2369,2371,2373,2375,2377,2379,2381,2383,2385,2387,2389,2391],{"class":71,"line":120},[69,2364,172],{"class":128},[69,2366,132],{"class":83},[69,2368,178],{"class":177},[69,2370,132],{"class":83},[69,2372,48],{"class":128},[69,2374,132],{"class":83},[69,2376,136],{"class":135},[69,2378,140],{"class":139},[69,2380,143],{"class":83},[69,2382,147],{"class":146},[69,2384,294],{"class":79},[69,2386,94],{"class":87},[69,2388,91],{"class":83},[69,2390,163],{"class":146},[69,2392,2019],{"class":83},[20,2394,321],{},[60,2396,2398],{"className":62,"code":2397,"language":64,"meta":65,"style":65},"[3, 4]\n",[15,2399,2400],{"__ignoreMap":65},[69,2401,2402,2404,2406,2408,2410],{"class":71,"line":72},[69,2403,331],{"class":83},[69,2405,346],{"class":87},[69,2407,91],{"class":83},[69,2409,104],{"class":87},[69,2411,117],{"class":83},[20,2413,2329,2414,143],{},[15,2415,2314],{},[60,2417,2419],{"className":62,"code":2418,"language":64,"meta":65,"style":65},"numbers = [1, 2, 3, 4]\nprint(list(map(lambda x: x * 2, numbers)))\n",[15,2420,2421,2445],{"__ignoreMap":65},[69,2422,2423,2425,2427,2429,2431,2433,2435,2437,2439,2441,2443],{"class":71,"line":72},[69,2424,76],{"class":75},[69,2426,80],{"class":79},[69,2428,84],{"class":83},[69,2430,88],{"class":87},[69,2432,91],{"class":83},[69,2434,94],{"class":87},[69,2436,91],{"class":83},[69,2438,99],{"class":87},[69,2440,91],{"class":83},[69,2442,104],{"class":87},[69,2444,117],{"class":83},[69,2446,2447,2449,2451,2453,2455,2458,2460,2462,2464,2466,2468,2471,2473,2475,2477],{"class":71,"line":120},[69,2448,172],{"class":128},[69,2450,132],{"class":83},[69,2452,178],{"class":177},[69,2454,132],{"class":83},[69,2456,2457],{"class":128},"map",[69,2459,132],{"class":83},[69,2461,136],{"class":135},[69,2463,140],{"class":139},[69,2465,143],{"class":83},[69,2467,147],{"class":146},[69,2469,2470],{"class":79},"*",[69,2472,94],{"class":87},[69,2474,91],{"class":83},[69,2476,163],{"class":146},[69,2478,2019],{"class":83},[20,2480,321],{},[60,2482,2484],{"className":62,"code":2483,"language":64,"meta":65,"style":65},"[2, 4, 6, 8]\n",[15,2485,2486],{"__ignoreMap":65},[69,2487,2488,2490,2492,2494,2496,2498,2500,2502,2505],{"class":71,"line":72},[69,2489,331],{"class":83},[69,2491,1155],{"class":87},[69,2493,91],{"class":83},[69,2495,104],{"class":87},[69,2497,91],{"class":83},[69,2499,114],{"class":87},[69,2501,91],{"class":83},[69,2503,2504],{"class":87}," 8",[69,2506,117],{"class":83},[20,2508,2509,2510,537],{},"For the related function, see ",[533,2511,13,2513,2515],{"href":2512},"\u002Freference\u002Fpython-map-function-explained\u002F",[15,2514,2314],{}," function explained",[55,2517,2519],{"id":2518},"faq","FAQ",[377,2521,2523,2524,2526],{"id":2522},"does-filter-return-a-list-in-python-3","Does ",[15,2525,17],{}," return a list in Python 3?",[20,2528,2529,2530,2532],{},"No. In Python 3, it returns a filter object. Convert it with ",[15,2531,52],{}," if needed.",[377,2534,2536,2537,2539],{"id":2535},"what-does-the-function-inside-filter-need-to-return","What does the function inside ",[15,2538,17],{}," need to return?",[20,2541,391,2542,2544,2545,2547],{},[15,2543,224],{}," to keep an item and ",[15,2546,230],{}," to remove it.",[377,2549,2551,2552,2554],{"id":2550},"can-i-use-filter-without-lambda","Can I use ",[15,2553,17],{}," without lambda?",[20,2556,2557],{},"Yes. You can pass a regular named function.",[377,2559,2561,2562,2565],{"id":2560},"what-does-filternone-items-do","What does ",[15,2563,2564],{},"filter(None, items)"," do?",[20,2567,2568,2569,2571,2572,2574,2575,537],{},"It removes falsy values such as ",[15,2570,1226],{},", empty strings, ",[15,2573,1181],{},", and ",[15,2576,230],{},[377,2578,2580,2581,2583],{"id":2579},"should-i-use-filter-or-a-list-comprehension","Should I use ",[15,2582,17],{}," or a list comprehension?",[20,2585,2586,2587,2589],{},"Both work. Many beginners find list comprehensions or ",[15,2588,1514],{}," loops easier to read.",[20,2591,2592],{},"If your goal is simple filtering:",[29,2594,2595,2601,2607],{},[32,2596,2597,2598,2600],{},"use ",[15,2599,17],{}," when you already have a test function or want a functional style",[32,2602,2603,2604,2606],{},"use a ",[15,2605,1514],{}," loop when you want the clearest step-by-step logic",[32,2608,2609],{},"use a list comprehension when you want a short and readable result list",[20,2611,2612,2613,537],{},"For a task-based example, see ",[533,2614,2616],{"href":2615},"\u002Fhow-to\u002Fhow-to-filter-a-list-in-python\u002F","how to filter a list in Python",[55,2618,2620],{"id":2619},"see-also","See also",[29,2622,2623,2628,2633,2638,2644],{},[32,2624,2625],{},[533,2626,2627],{"href":1000},"Lambda functions in Python explained",[32,2629,2630],{},[533,2631,2632],{"href":2615},"How to filter a list in Python",[32,2634,2635],{},[533,2636,2637],{"href":1766},"List comprehensions in Python explained",[32,2639,2640],{},[533,2641,13,2642,2515],{"href":2512},[15,2643,2314],{},[32,2645,2646],{},[533,2647,2648],{"href":535},"Iterators and iterable objects explained",[2650,2651,2652],"style",{},"html pre.shiki code .su5hD, html code.shiki .su5hD{--shiki-light:#90A4AE;--shiki-default:#24292E;--shiki-dark:#E1E4E8}html pre.shiki code .smGrS, html code.shiki .smGrS{--shiki-light:#39ADB5;--shiki-default:#D73A49;--shiki-dark:#F97583}html pre.shiki code .sP7_E, html code.shiki .sP7_E{--shiki-light:#39ADB5;--shiki-default:#24292E;--shiki-dark:#E1E4E8}html pre.shiki code .srdBf, html code.shiki .srdBf{--shiki-light:#F76D47;--shiki-default:#005CC5;--shiki-dark:#79B8FF}html pre.shiki code .sptTA, html code.shiki .sptTA{--shiki-light:#6182B8;--shiki-default:#005CC5;--shiki-dark:#79B8FF}html pre.shiki code .sbsja, html code.shiki .sbsja{--shiki-light:#9C3EDA;--shiki-default:#D73A49;--shiki-dark:#F97583}html pre.shiki code .sFwrP, html code.shiki .sFwrP{--shiki-light:#90A4AE;--shiki-light-font-style:italic;--shiki-default:#24292E;--shiki-default-font-style:inherit;--shiki-dark:#E1E4E8;--shiki-dark-font-style:inherit}html pre.shiki code .slqww, html code.shiki .slqww{--shiki-light:#6182B8;--shiki-default:#24292E;--shiki-dark:#E1E4E8}html pre.shiki code .sZMiF, html code.shiki .sZMiF{--shiki-light:#E2931D;--shiki-default:#005CC5;--shiki-dark:#79B8FF}html pre.shiki code .sutJx, html code.shiki .sutJx{--shiki-light:#90A4AE;--shiki-light-font-style:italic;--shiki-default:#6A737D;--shiki-default-font-style:inherit;--shiki-dark:#6A737D;--shiki-dark-font-style:inherit}html .light .shiki span {color: var(--shiki-light);background: var(--shiki-light-bg);font-style: var(--shiki-light-font-style);font-weight: var(--shiki-light-font-weight);text-decoration: var(--shiki-light-text-decoration);}html.light .shiki span {color: var(--shiki-light);background: var(--shiki-light-bg);font-style: var(--shiki-light-font-style);font-weight: var(--shiki-light-font-weight);text-decoration: var(--shiki-light-text-decoration);}html .default .shiki span {color: var(--shiki-default);background: var(--shiki-default-bg);font-style: var(--shiki-default-font-style);font-weight: var(--shiki-default-font-weight);text-decoration: var(--shiki-default-text-decoration);}html .shiki span {color: var(--shiki-default);background: var(--shiki-default-bg);font-style: var(--shiki-default-font-style);font-weight: var(--shiki-default-font-weight);text-decoration: var(--shiki-default-text-decoration);}html .dark .shiki span {color: var(--shiki-dark);background: var(--shiki-dark-bg);font-style: var(--shiki-dark-font-style);font-weight: var(--shiki-dark-font-weight);text-decoration: var(--shiki-dark-text-decoration);}html.dark .shiki span {color: var(--shiki-dark);background: var(--shiki-dark-bg);font-style: var(--shiki-dark-font-style);font-weight: var(--shiki-dark-font-weight);text-decoration: var(--shiki-dark-text-decoration);}html pre.shiki code .s_hVV, html code.shiki .s_hVV{--shiki-light:#90A4AE;--shiki-default:#005CC5;--shiki-dark:#79B8FF}html pre.shiki code .sjJ54, html code.shiki .sjJ54{--shiki-light:#39ADB5;--shiki-default:#032F62;--shiki-dark:#9ECBFF}html pre.shiki code .s_sjI, html code.shiki .s_sjI{--shiki-light:#91B859;--shiki-default:#032F62;--shiki-dark:#9ECBFF}html pre.shiki code .sGLFI, html code.shiki .sGLFI{--shiki-light:#6182B8;--shiki-default:#6F42C1;--shiki-dark:#B392F0}html pre.shiki code .sVHd0, html code.shiki .sVHd0{--shiki-light:#39ADB5;--shiki-light-font-style:italic;--shiki-default:#D73A49;--shiki-default-font-style:inherit;--shiki-dark:#F97583;--shiki-dark-font-style:inherit}html pre.shiki code .s39Yj, html code.shiki .s39Yj{--shiki-light:#39ADB5;--shiki-default:#005CC5;--shiki-dark:#79B8FF}",{"title":65,"searchDepth":120,"depth":120,"links":2654},[2655,2656,2658,2662,2665,2667,2669,2671,2673,2683,2695],{"id":57,"depth":120,"text":58},{"id":201,"depth":120,"text":2657},"What filter() does",{"id":350,"depth":120,"text":351,"children":2659},[2660,2661],{"id":368,"depth":169,"text":368},{"id":399,"depth":169,"text":399},{"id":540,"depth":120,"text":541,"children":2663},[2664],{"id":726,"depth":169,"text":727},{"id":839,"depth":120,"text":2666},"Using filter() with lambda",{"id":1004,"depth":120,"text":2668},"Using filter() with a named function",{"id":1178,"depth":120,"text":2670},"Using None with filter()",{"id":1372,"depth":120,"text":2672},"When to use filter()",{"id":1770,"depth":120,"text":1771,"children":2674},[2675,2677,2679,2680,2681],{"id":1779,"depth":169,"text":2676},"Expecting filter() to return a list",{"id":1913,"depth":169,"text":2678},"Using a test function that does not return True or False clearly",{"id":2041,"depth":169,"text":2042},{"id":2228,"depth":169,"text":2229},{"id":2308,"depth":169,"text":2682},"Confusing filter() with map()",{"id":2518,"depth":120,"text":2519,"children":2684},[2685,2687,2689,2691,2693],{"id":2522,"depth":169,"text":2686},"Does filter() return a list in Python 3?",{"id":2535,"depth":169,"text":2688},"What does the function inside filter() need to return?",{"id":2550,"depth":169,"text":2690},"Can I use filter() without lambda?",{"id":2560,"depth":169,"text":2692},"What does filter(None, items) do?",{"id":2579,"depth":169,"text":2694},"Should I use filter() or a list comprehension?",{"id":2619,"depth":120,"text":2620},"Master python filter function explained in our comprehensive Python beginner guide.","md",{},"\u002Freference\u002Fpython-filter-function-explained",{"title":5,"description":2696},"reference\u002Fpython-filter-function-explained","J9FdKm1wa-c3gDwJ_QQuBfzCHZa4aHKoE2spSvz7L8I",1777585503330]