[{"data":1,"prerenderedAt":2617},["ShallowReactive",2],{"doc-\u002Freference\u002Fpython-dictionary-fromkeys-method":3},{"id":4,"title":5,"body":6,"description":2610,"extension":2611,"meta":2612,"navigation":357,"path":2613,"seo":2614,"stem":2615,"__hash__":2616},"content\u002Freference\u002Fpython-dictionary-fromkeys-method.md","Python Dictionary fromkeys() Method",{"type":7,"value":8,"toc":2566},"minimark",[9,19,26,29,32,37,154,161,168,173,193,206,214,218,243,248,261,270,274,281,285,288,370,373,422,425,443,450,457,462,538,540,587,590,601,604,730,732,785,792,796,799,819,825,829,934,936,989,996,1000,1006,1009,1012,1039,1044,1048,1051,1160,1162,1207,1210,1213,1219,1224,1235,1238,1302,1364,1371,1379,1385,1390,1395,1458,1462,1533,1536,1540,1611,1614,1627,1638,1642,1647,1651,1722,1724,1761,1764,1767,1830,1837,1840,1882,1893,1896,1965,1972,1977,2066,2068,2117,2124,2130,2177,2179,2212,2217,2221,2227,2267,2311,2379,2426,2430,2437,2440,2444,2449,2453,2456,2460,2462,2523,2527,2557,2562],[10,11,13,14,18],"h1",{"id":12},"python-dictionary-fromkeys-method","Python Dictionary ",[15,16,17],"code",{},"fromkeys()"," Method",[20,21,22,25],"p",{},[15,23,24],{},"dict.fromkeys()"," creates a new dictionary from a group of keys.",[20,27,28],{},"It is useful when you already know the keys you want, and every key should start with the same value.",[20,30,31],{},"One important beginner mistake to watch for is using a mutable value like a list or dictionary. In that case, all keys share the same object.",[33,34,36],"h2",{"id":35},"quick-example","Quick example",[38,39,44],"pre",{"className":40,"code":41,"language":42,"meta":43,"style":43},"language-python shiki shiki-themes material-theme-lighter github-light github-dark","keys = [\"name\", \"age\", \"city\"]\nperson = dict.fromkeys(keys, \"unknown\")\nprint(person)\n# {'name': 'unknown', 'age': 'unknown', 'city': 'unknown'}\n","python","",[15,45,46,96,133,147],{"__ignoreMap":43},[47,48,51,55,59,63,67,71,73,76,79,82,84,86,88,91,93],"span",{"class":49,"line":50},"line",1,[47,52,54],{"class":53},"su5hD","keys ",[47,56,58],{"class":57},"smGrS","=",[47,60,62],{"class":61},"sP7_E"," [",[47,64,66],{"class":65},"sjJ54","\"",[47,68,70],{"class":69},"s_sjI","name",[47,72,66],{"class":65},[47,74,75],{"class":61},",",[47,77,78],{"class":65}," \"",[47,80,81],{"class":69},"age",[47,83,66],{"class":65},[47,85,75],{"class":61},[47,87,78],{"class":65},[47,89,90],{"class":69},"city",[47,92,66],{"class":65},[47,94,95],{"class":61},"]\n",[47,97,99,102,104,108,111,115,118,121,123,125,128,130],{"class":49,"line":98},2,[47,100,101],{"class":53},"person ",[47,103,58],{"class":57},[47,105,107],{"class":106},"sZMiF"," dict",[47,109,110],{"class":61},".",[47,112,114],{"class":113},"slqww","fromkeys",[47,116,117],{"class":61},"(",[47,119,120],{"class":113},"keys",[47,122,75],{"class":61},[47,124,78],{"class":65},[47,126,127],{"class":69},"unknown",[47,129,66],{"class":65},[47,131,132],{"class":61},")\n",[47,134,136,140,142,145],{"class":49,"line":135},3,[47,137,139],{"class":138},"sptTA","print",[47,141,117],{"class":61},[47,143,144],{"class":113},"person",[47,146,132],{"class":61},[47,148,150],{"class":49,"line":149},4,[47,151,153],{"class":152},"sutJx","# {'name': 'unknown', 'age': 'unknown', 'city': 'unknown'}\n",[20,155,156,157,160],{},"Use ",[15,158,159],{},"dict.fromkeys(iterable, value)"," to create a new dictionary where each key starts with the same value.",[33,162,164,165,167],{"id":163},"what-dictfromkeys-does","What ",[15,166,24],{}," does",[20,169,170,172],{},[15,171,24],{},":",[174,175,176,180,183,186],"ul",{},[177,178,179],"li",{},"Creates a new dictionary from a sequence of keys",[177,181,182],{},"Assigns the same value to every key",[177,184,185],{},"Returns a new dictionary",[177,187,188,189,192],{},"Is called as ",[15,190,191],{},"dict.fromkeys(...)",", not on an existing dictionary",[20,194,195,196,199,200,202,203,110],{},"This is a class method on ",[15,197,198],{},"dict",", so you write ",[15,201,191],{}," instead of something like ",[15,204,205],{},"my_dict.fromkeys(...)",[20,207,208,209,110],{},"If you need a refresher on dictionaries first, see ",[210,211,213],"a",{"href":212},"\u002Flearn\u002Fpython-dictionaries-explained","Python dictionaries explained",[33,215,217],{"id":216},"syntax-and-parameters","Syntax and parameters",[38,219,221],{"className":40,"code":220,"language":42,"meta":43,"style":43},"dict.fromkeys(iterable, value)\n",[15,222,223],{"__ignoreMap":43},[47,224,225,227,229,231,233,236,238,241],{"class":49,"line":50},[47,226,198],{"class":106},[47,228,110],{"class":61},[47,230,114],{"class":113},[47,232,117],{"class":61},[47,234,235],{"class":113},"iterable",[47,237,75],{"class":61},[47,239,240],{"class":113}," value",[47,242,132],{"class":61},[244,245,247],"h3",{"id":246},"parameters","Parameters",[174,249,250,255],{},[177,251,252,254],{},[15,253,235],{},": the keys to use",[177,256,257,260],{},[15,258,259],{},"value",": optional starting value for every key",[20,262,263,264,266,267,110],{},"If you leave out ",[15,265,259],{},", each key gets ",[15,268,269],{},"None",[244,271,273],{"id":272},"return-value","Return value",[20,275,276,277,110],{},"It returns a ",[278,279,280],"strong",{},"new dictionary",[33,282,284],{"id":283},"basic-example","Basic example",[20,286,287],{},"Here is a simple example using a list of strings as keys:",[38,289,291],{"className":40,"code":290,"language":42,"meta":43,"style":43},"keys = [\"red\", \"green\", \"blue\"]\ncolors = dict.fromkeys(keys, 0)\n\nprint(colors)\n",[15,292,293,328,353,359],{"__ignoreMap":43},[47,294,295,297,299,301,303,306,308,310,312,315,317,319,321,324,326],{"class":49,"line":50},[47,296,54],{"class":53},[47,298,58],{"class":57},[47,300,62],{"class":61},[47,302,66],{"class":65},[47,304,305],{"class":69},"red",[47,307,66],{"class":65},[47,309,75],{"class":61},[47,311,78],{"class":65},[47,313,314],{"class":69},"green",[47,316,66],{"class":65},[47,318,75],{"class":61},[47,320,78],{"class":65},[47,322,323],{"class":69},"blue",[47,325,66],{"class":65},[47,327,95],{"class":61},[47,329,330,333,335,337,339,341,343,345,347,351],{"class":49,"line":98},[47,331,332],{"class":53},"colors ",[47,334,58],{"class":57},[47,336,107],{"class":106},[47,338,110],{"class":61},[47,340,114],{"class":113},[47,342,117],{"class":61},[47,344,120],{"class":113},[47,346,75],{"class":61},[47,348,350],{"class":349},"srdBf"," 0",[47,352,132],{"class":61},[47,354,355],{"class":49,"line":135},[47,356,358],{"emptyLinePlaceholder":357},true,"\n",[47,360,361,363,365,368],{"class":49,"line":149},[47,362,139],{"class":138},[47,364,117],{"class":61},[47,366,367],{"class":113},"colors",[47,369,132],{"class":61},[20,371,372],{},"Output:",[38,374,376],{"className":40,"code":375,"language":42,"meta":43,"style":43},"{'red': 0, 'green': 0, 'blue': 0}\n",[15,377,378],{"__ignoreMap":43},[47,379,380,383,386,388,390,392,394,396,399,401,403,405,407,409,411,413,415,417,419],{"class":49,"line":50},[47,381,382],{"class":61},"{",[47,384,385],{"class":65},"'",[47,387,305],{"class":69},[47,389,385],{"class":65},[47,391,172],{"class":61},[47,393,350],{"class":349},[47,395,75],{"class":61},[47,397,398],{"class":65}," '",[47,400,314],{"class":69},[47,402,385],{"class":65},[47,404,172],{"class":61},[47,406,350],{"class":349},[47,408,75],{"class":61},[47,410,398],{"class":65},[47,412,323],{"class":69},[47,414,385],{"class":65},[47,416,172],{"class":61},[47,418,350],{"class":349},[47,420,421],{"class":61},"}\n",[20,423,424],{},"What happens here:",[174,426,427,432,438],{},[177,428,429,431],{},[15,430,120],{}," contains the dictionary keys",[177,433,434,437],{},[15,435,436],{},"0"," is used as the starting value for every key",[177,439,440,442],{},[15,441,24],{}," returns the new dictionary",[20,444,445,446,110],{},"If you want to learn more ways to create dictionaries, see ",[210,447,449],{"href":448},"\u002Freference\u002Fpython-dictionary-creating-a-dictionary","creating a dictionary in Python",[33,451,453,454,456],{"id":452},"using-fromkeys-without-a-value","Using ",[15,455,17],{}," without a value",[20,458,459,460,110],{},"If you do not pass the second argument, the default value is ",[15,461,269],{},[38,463,465],{"className":40,"code":464,"language":42,"meta":43,"style":43},"fields = [\"username\", \"email\", \"password\"]\nuser_data = dict.fromkeys(fields)\n\nprint(user_data)\n",[15,466,467,503,523,527],{"__ignoreMap":43},[47,468,469,472,474,476,478,481,483,485,487,490,492,494,496,499,501],{"class":49,"line":50},[47,470,471],{"class":53},"fields ",[47,473,58],{"class":57},[47,475,62],{"class":61},[47,477,66],{"class":65},[47,479,480],{"class":69},"username",[47,482,66],{"class":65},[47,484,75],{"class":61},[47,486,78],{"class":65},[47,488,489],{"class":69},"email",[47,491,66],{"class":65},[47,493,75],{"class":61},[47,495,78],{"class":65},[47,497,498],{"class":69},"password",[47,500,66],{"class":65},[47,502,95],{"class":61},[47,504,505,508,510,512,514,516,518,521],{"class":49,"line":98},[47,506,507],{"class":53},"user_data ",[47,509,58],{"class":57},[47,511,107],{"class":106},[47,513,110],{"class":61},[47,515,114],{"class":113},[47,517,117],{"class":61},[47,519,520],{"class":113},"fields",[47,522,132],{"class":61},[47,524,525],{"class":49,"line":135},[47,526,358],{"emptyLinePlaceholder":357},[47,528,529,531,533,536],{"class":49,"line":149},[47,530,139],{"class":138},[47,532,117],{"class":61},[47,534,535],{"class":113},"user_data",[47,537,132],{"class":61},[20,539,372],{},[38,541,543],{"className":40,"code":542,"language":42,"meta":43,"style":43},"{'username': None, 'email': None, 'password': None}\n",[15,544,545],{"__ignoreMap":43},[47,546,547,549,551,553,555,557,561,563,565,567,569,571,573,575,577,579,581,583,585],{"class":49,"line":50},[47,548,382],{"class":61},[47,550,385],{"class":65},[47,552,480],{"class":69},[47,554,385],{"class":65},[47,556,172],{"class":61},[47,558,560],{"class":559},"s39Yj"," None",[47,562,75],{"class":61},[47,564,398],{"class":65},[47,566,489],{"class":69},[47,568,385],{"class":65},[47,570,172],{"class":61},[47,572,560],{"class":559},[47,574,75],{"class":61},[47,576,398],{"class":65},[47,578,498],{"class":69},[47,580,385],{"class":65},[47,582,172],{"class":61},[47,584,560],{"class":559},[47,586,421],{"class":61},[20,588,589],{},"This is useful when:",[174,591,592,595,598],{},[177,593,594],{},"You want to create the keys first",[177,596,597],{},"You plan to fill in the real values later",[177,599,600],{},"You need placeholder values during setup",[20,602,603],{},"Example:",[38,605,607],{"className":40,"code":606,"language":42,"meta":43,"style":43},"fields = [\"username\", \"email\", \"password\"]\nuser_data = dict.fromkeys(fields)\n\nuser_data[\"username\"] = \"alice\"\nuser_data[\"email\"] = \"alice@example.com\"\n\nprint(user_data)\n",[15,608,609,641,659,663,690,714,719],{"__ignoreMap":43},[47,610,611,613,615,617,619,621,623,625,627,629,631,633,635,637,639],{"class":49,"line":50},[47,612,471],{"class":53},[47,614,58],{"class":57},[47,616,62],{"class":61},[47,618,66],{"class":65},[47,620,480],{"class":69},[47,622,66],{"class":65},[47,624,75],{"class":61},[47,626,78],{"class":65},[47,628,489],{"class":69},[47,630,66],{"class":65},[47,632,75],{"class":61},[47,634,78],{"class":65},[47,636,498],{"class":69},[47,638,66],{"class":65},[47,640,95],{"class":61},[47,642,643,645,647,649,651,653,655,657],{"class":49,"line":98},[47,644,507],{"class":53},[47,646,58],{"class":57},[47,648,107],{"class":106},[47,650,110],{"class":61},[47,652,114],{"class":113},[47,654,117],{"class":61},[47,656,520],{"class":113},[47,658,132],{"class":61},[47,660,661],{"class":49,"line":135},[47,662,358],{"emptyLinePlaceholder":357},[47,664,665,667,670,672,674,676,679,682,684,687],{"class":49,"line":149},[47,666,535],{"class":53},[47,668,669],{"class":61},"[",[47,671,66],{"class":65},[47,673,480],{"class":69},[47,675,66],{"class":65},[47,677,678],{"class":61},"]",[47,680,681],{"class":57}," =",[47,683,78],{"class":65},[47,685,686],{"class":69},"alice",[47,688,689],{"class":65},"\"\n",[47,691,693,695,697,699,701,703,705,707,709,712],{"class":49,"line":692},5,[47,694,535],{"class":53},[47,696,669],{"class":61},[47,698,66],{"class":65},[47,700,489],{"class":69},[47,702,66],{"class":65},[47,704,678],{"class":61},[47,706,681],{"class":57},[47,708,78],{"class":65},[47,710,711],{"class":69},"alice@example.com",[47,713,689],{"class":65},[47,715,717],{"class":49,"line":716},6,[47,718,358],{"emptyLinePlaceholder":357},[47,720,722,724,726,728],{"class":49,"line":721},7,[47,723,139],{"class":138},[47,725,117],{"class":61},[47,727,535],{"class":113},[47,729,132],{"class":61},[20,731,372],{},[38,733,735],{"className":40,"code":734,"language":42,"meta":43,"style":43},"{'username': 'alice', 'email': 'alice@example.com', 'password': None}\n",[15,736,737],{"__ignoreMap":43},[47,738,739,741,743,745,747,749,751,753,755,757,759,761,763,765,767,769,771,773,775,777,779,781,783],{"class":49,"line":50},[47,740,382],{"class":61},[47,742,385],{"class":65},[47,744,480],{"class":69},[47,746,385],{"class":65},[47,748,172],{"class":61},[47,750,398],{"class":65},[47,752,686],{"class":69},[47,754,385],{"class":65},[47,756,75],{"class":61},[47,758,398],{"class":65},[47,760,489],{"class":69},[47,762,385],{"class":65},[47,764,172],{"class":61},[47,766,398],{"class":65},[47,768,711],{"class":69},[47,770,385],{"class":65},[47,772,75],{"class":61},[47,774,398],{"class":65},[47,776,498],{"class":69},[47,778,385],{"class":65},[47,780,172],{"class":61},[47,782,560],{"class":559},[47,784,421],{"class":61},[20,786,787,788,110],{},"If you want to add or change keys later, see ",[210,789,791],{"href":790},"\u002Fhow-to\u002Fhow-to-add-a-key-to-a-dictionary-in-python","how to add a key to a dictionary in Python",[33,793,795],{"id":794},"important-warning-about-mutable-values","Important warning about mutable values",[20,797,798],{},"Be careful when using a mutable value such as:",[174,800,801,807,813],{},[177,802,803,806],{},[15,804,805],{},"[]"," (list)",[177,808,809,812],{},[15,810,811],{},"{}"," (dictionary)",[177,814,815,818],{},[15,816,817],{},"set()"," (set)",[20,820,821,822,110],{},"All keys will point to the ",[278,823,824],{},"same object",[244,826,828],{"id":827},"example-of-the-problem","Example of the problem",[38,830,832],{"className":40,"code":831,"language":42,"meta":43,"style":43},"keys = [\"a\", \"b\", \"c\"]\ndata = dict.fromkeys(keys, [])\n\ndata[\"a\"].append(1)\n\nprint(data)\n",[15,833,834,868,890,894,920,924],{"__ignoreMap":43},[47,835,836,838,840,842,844,846,848,850,852,855,857,859,861,864,866],{"class":49,"line":50},[47,837,54],{"class":53},[47,839,58],{"class":57},[47,841,62],{"class":61},[47,843,66],{"class":65},[47,845,210],{"class":69},[47,847,66],{"class":65},[47,849,75],{"class":61},[47,851,78],{"class":65},[47,853,854],{"class":69},"b",[47,856,66],{"class":65},[47,858,75],{"class":61},[47,860,78],{"class":65},[47,862,863],{"class":69},"c",[47,865,66],{"class":65},[47,867,95],{"class":61},[47,869,870,873,875,877,879,881,883,885,887],{"class":49,"line":98},[47,871,872],{"class":53},"data ",[47,874,58],{"class":57},[47,876,107],{"class":106},[47,878,110],{"class":61},[47,880,114],{"class":113},[47,882,117],{"class":61},[47,884,120],{"class":113},[47,886,75],{"class":61},[47,888,889],{"class":61}," [])\n",[47,891,892],{"class":49,"line":135},[47,893,358],{"emptyLinePlaceholder":357},[47,895,896,899,901,903,905,907,910,913,915,918],{"class":49,"line":149},[47,897,898],{"class":53},"data",[47,900,669],{"class":61},[47,902,66],{"class":65},[47,904,210],{"class":69},[47,906,66],{"class":65},[47,908,909],{"class":61},"].",[47,911,912],{"class":113},"append",[47,914,117],{"class":61},[47,916,917],{"class":349},"1",[47,919,132],{"class":61},[47,921,922],{"class":49,"line":692},[47,923,358],{"emptyLinePlaceholder":357},[47,925,926,928,930,932],{"class":49,"line":716},[47,927,139],{"class":138},[47,929,117],{"class":61},[47,931,898],{"class":113},[47,933,132],{"class":61},[20,935,372],{},[38,937,939],{"className":40,"code":938,"language":42,"meta":43,"style":43},"{'a': [1], 'b': [1], 'c': [1]}\n",[15,940,941],{"__ignoreMap":43},[47,942,943,945,947,949,951,953,955,957,960,962,964,966,968,970,972,974,976,978,980,982,984,986],{"class":49,"line":50},[47,944,382],{"class":61},[47,946,385],{"class":65},[47,948,210],{"class":69},[47,950,385],{"class":65},[47,952,172],{"class":61},[47,954,62],{"class":61},[47,956,917],{"class":349},[47,958,959],{"class":61},"],",[47,961,398],{"class":65},[47,963,854],{"class":69},[47,965,385],{"class":65},[47,967,172],{"class":61},[47,969,62],{"class":61},[47,971,917],{"class":349},[47,973,959],{"class":61},[47,975,398],{"class":65},[47,977,863],{"class":69},[47,979,385],{"class":65},[47,981,172],{"class":61},[47,983,62],{"class":61},[47,985,917],{"class":349},[47,987,988],{"class":61},"]}\n",[20,990,991,992,995],{},"Many beginners expect only ",[15,993,994],{},"\"a\""," to change, but all keys change because they share the same list.",[244,997,999],{"id":998},"why-this-happens","Why this happens",[20,1001,1002,1005],{},[15,1003,1004],{},"dict.fromkeys(keys, [])"," creates one list object.",[20,1007,1008],{},"That same list is then used for every key.",[20,1010,1011],{},"So this:",[38,1013,1015],{"className":40,"code":1014,"language":42,"meta":43,"style":43},"data[\"a\"].append(1)\n",[15,1016,1017],{"__ignoreMap":43},[47,1018,1019,1021,1023,1025,1027,1029,1031,1033,1035,1037],{"class":49,"line":50},[47,1020,898],{"class":53},[47,1022,669],{"class":61},[47,1024,66],{"class":65},[47,1026,210],{"class":69},[47,1028,66],{"class":65},[47,1030,909],{"class":61},[47,1032,912],{"class":113},[47,1034,117],{"class":61},[47,1036,917],{"class":349},[47,1038,132],{"class":61},[20,1040,1041,1042,110],{},"changes the shared list, not a separate list just for key ",[15,1043,994],{},[244,1045,1047],{"id":1046},"the-better-way-when-each-key-needs-its-own-list","The better way when each key needs its own list",[20,1049,1050],{},"Use a dictionary comprehension:",[38,1052,1054],{"className":40,"code":1053,"language":42,"meta":43,"style":43},"keys = [\"a\", \"b\", \"c\"]\ndata = {key: [] for key in keys}\n\ndata[\"a\"].append(1)\n\nprint(data)\n",[15,1055,1056,1088,1120,1124,1146,1150],{"__ignoreMap":43},[47,1057,1058,1060,1062,1064,1066,1068,1070,1072,1074,1076,1078,1080,1082,1084,1086],{"class":49,"line":50},[47,1059,54],{"class":53},[47,1061,58],{"class":57},[47,1063,62],{"class":61},[47,1065,66],{"class":65},[47,1067,210],{"class":69},[47,1069,66],{"class":65},[47,1071,75],{"class":61},[47,1073,78],{"class":65},[47,1075,854],{"class":69},[47,1077,66],{"class":65},[47,1079,75],{"class":61},[47,1081,78],{"class":65},[47,1083,863],{"class":69},[47,1085,66],{"class":65},[47,1087,95],{"class":61},[47,1089,1090,1092,1094,1097,1100,1102,1105,1109,1112,1115,1118],{"class":49,"line":98},[47,1091,872],{"class":53},[47,1093,58],{"class":57},[47,1095,1096],{"class":61}," {",[47,1098,1099],{"class":53},"key",[47,1101,172],{"class":61},[47,1103,1104],{"class":61}," []",[47,1106,1108],{"class":1107},"sVHd0"," for",[47,1110,1111],{"class":53}," key ",[47,1113,1114],{"class":1107},"in",[47,1116,1117],{"class":53}," keys",[47,1119,421],{"class":61},[47,1121,1122],{"class":49,"line":135},[47,1123,358],{"emptyLinePlaceholder":357},[47,1125,1126,1128,1130,1132,1134,1136,1138,1140,1142,1144],{"class":49,"line":149},[47,1127,898],{"class":53},[47,1129,669],{"class":61},[47,1131,66],{"class":65},[47,1133,210],{"class":69},[47,1135,66],{"class":65},[47,1137,909],{"class":61},[47,1139,912],{"class":113},[47,1141,117],{"class":61},[47,1143,917],{"class":349},[47,1145,132],{"class":61},[47,1147,1148],{"class":49,"line":692},[47,1149,358],{"emptyLinePlaceholder":357},[47,1151,1152,1154,1156,1158],{"class":49,"line":716},[47,1153,139],{"class":138},[47,1155,117],{"class":61},[47,1157,898],{"class":113},[47,1159,132],{"class":61},[20,1161,372],{},[38,1163,1165],{"className":40,"code":1164,"language":42,"meta":43,"style":43},"{'a': [1], 'b': [], 'c': []}\n",[15,1166,1167],{"__ignoreMap":43},[47,1168,1169,1171,1173,1175,1177,1179,1181,1183,1185,1187,1189,1191,1193,1196,1198,1200,1202,1204],{"class":49,"line":50},[47,1170,382],{"class":61},[47,1172,385],{"class":65},[47,1174,210],{"class":69},[47,1176,385],{"class":65},[47,1178,172],{"class":61},[47,1180,62],{"class":61},[47,1182,917],{"class":349},[47,1184,959],{"class":61},[47,1186,398],{"class":65},[47,1188,854],{"class":69},[47,1190,385],{"class":65},[47,1192,172],{"class":61},[47,1194,1195],{"class":61}," [],",[47,1197,398],{"class":65},[47,1199,863],{"class":69},[47,1201,385],{"class":65},[47,1203,172],{"class":61},[47,1205,1206],{"class":61}," []}\n",[20,1208,1209],{},"Now each key has its own separate list.",[20,1211,1212],{},"This same rule applies if you want each key to have its own dictionary or set.",[33,1214,1216,1217],{"id":1215},"when-to-use-fromkeys","When to use ",[15,1218,17],{},[20,1220,1221,1223],{},[15,1222,24],{}," is a good choice when:",[174,1225,1226,1229,1232],{},[177,1227,1228],{},"You want to quickly create a dictionary with known keys",[177,1230,1231],{},"Every key should start with the same simple value",[177,1233,1234],{},"You need default flags, counters, or placeholders",[20,1236,1237],{},"Examples:",[38,1239,1241],{"className":40,"code":1240,"language":42,"meta":43,"style":43},"flags = dict.fromkeys([\"is_admin\", \"is_active\", \"is_verified\"], False)\nprint(flags)\n",[15,1242,1243,1291],{"__ignoreMap":43},[47,1244,1245,1248,1250,1252,1254,1256,1259,1261,1264,1266,1268,1270,1273,1275,1277,1279,1282,1284,1286,1289],{"class":49,"line":50},[47,1246,1247],{"class":53},"flags ",[47,1249,58],{"class":57},[47,1251,107],{"class":106},[47,1253,110],{"class":61},[47,1255,114],{"class":113},[47,1257,1258],{"class":61},"([",[47,1260,66],{"class":65},[47,1262,1263],{"class":69},"is_admin",[47,1265,66],{"class":65},[47,1267,75],{"class":61},[47,1269,78],{"class":65},[47,1271,1272],{"class":69},"is_active",[47,1274,66],{"class":65},[47,1276,75],{"class":61},[47,1278,78],{"class":65},[47,1280,1281],{"class":69},"is_verified",[47,1283,66],{"class":65},[47,1285,959],{"class":61},[47,1287,1288],{"class":559}," False",[47,1290,132],{"class":61},[47,1292,1293,1295,1297,1300],{"class":49,"line":98},[47,1294,139],{"class":138},[47,1296,117],{"class":61},[47,1298,1299],{"class":113},"flags",[47,1301,132],{"class":61},[38,1303,1305],{"className":40,"code":1304,"language":42,"meta":43,"style":43},"scores = dict.fromkeys([\"math\", \"science\", \"history\"], 0)\nprint(scores)\n",[15,1306,1307,1353],{"__ignoreMap":43},[47,1308,1309,1312,1314,1316,1318,1320,1322,1324,1327,1329,1331,1333,1336,1338,1340,1342,1345,1347,1349,1351],{"class":49,"line":50},[47,1310,1311],{"class":53},"scores ",[47,1313,58],{"class":57},[47,1315,107],{"class":106},[47,1317,110],{"class":61},[47,1319,114],{"class":113},[47,1321,1258],{"class":61},[47,1323,66],{"class":65},[47,1325,1326],{"class":69},"math",[47,1328,66],{"class":65},[47,1330,75],{"class":61},[47,1332,78],{"class":65},[47,1334,1335],{"class":69},"science",[47,1337,66],{"class":65},[47,1339,75],{"class":61},[47,1341,78],{"class":65},[47,1343,1344],{"class":69},"history",[47,1346,66],{"class":65},[47,1348,959],{"class":61},[47,1350,350],{"class":349},[47,1352,132],{"class":61},[47,1354,1355,1357,1359,1362],{"class":49,"line":98},[47,1356,139],{"class":138},[47,1358,117],{"class":61},[47,1360,1361],{"class":113},"scores",[47,1363,132],{"class":61},[20,1365,1366,1367,1370],{},"It is ",[278,1368,1369],{},"not"," the best choice when:",[174,1372,1373,1376],{},[177,1374,1375],{},"Each key needs a different starting value",[177,1377,1378],{},"Each key needs its own new list or dictionary",[33,1380,1382,1384],{"id":1381},"fromkeys-vs-creating-a-dictionary-manually",[15,1383,17],{}," vs creating a dictionary manually",[20,1386,1387,1389],{},[15,1388,17],{}," is shorter when all keys share the same value.",[244,1391,453,1393],{"id":1392},"using-fromkeys",[15,1394,17],{},[38,1396,1398],{"className":40,"code":1397,"language":42,"meta":43,"style":43},"settings = dict.fromkeys([\"sound\", \"music\", \"notifications\"], True)\nprint(settings)\n",[15,1399,1400,1447],{"__ignoreMap":43},[47,1401,1402,1405,1407,1409,1411,1413,1415,1417,1420,1422,1424,1426,1429,1431,1433,1435,1438,1440,1442,1445],{"class":49,"line":50},[47,1403,1404],{"class":53},"settings ",[47,1406,58],{"class":57},[47,1408,107],{"class":106},[47,1410,110],{"class":61},[47,1412,114],{"class":113},[47,1414,1258],{"class":61},[47,1416,66],{"class":65},[47,1418,1419],{"class":69},"sound",[47,1421,66],{"class":65},[47,1423,75],{"class":61},[47,1425,78],{"class":65},[47,1427,1428],{"class":69},"music",[47,1430,66],{"class":65},[47,1432,75],{"class":61},[47,1434,78],{"class":65},[47,1436,1437],{"class":69},"notifications",[47,1439,66],{"class":65},[47,1441,959],{"class":61},[47,1443,1444],{"class":559}," True",[47,1446,132],{"class":61},[47,1448,1449,1451,1453,1456],{"class":49,"line":98},[47,1450,139],{"class":138},[47,1452,117],{"class":61},[47,1454,1455],{"class":113},"settings",[47,1457,132],{"class":61},[244,1459,1461],{"id":1460},"creating-a-dictionary-manually","Creating a dictionary manually",[38,1463,1465],{"className":40,"code":1464,"language":42,"meta":43,"style":43},"settings = {\n    \"sound\": True,\n    \"music\": False,\n    \"notifications\": True\n}\nprint(settings)\n",[15,1466,1467,1476,1492,1506,1519,1523],{"__ignoreMap":43},[47,1468,1469,1471,1473],{"class":49,"line":50},[47,1470,1404],{"class":53},[47,1472,58],{"class":57},[47,1474,1475],{"class":61}," {\n",[47,1477,1478,1481,1483,1485,1487,1489],{"class":49,"line":98},[47,1479,1480],{"class":65},"    \"",[47,1482,1419],{"class":69},[47,1484,66],{"class":65},[47,1486,172],{"class":61},[47,1488,1444],{"class":559},[47,1490,1491],{"class":61},",\n",[47,1493,1494,1496,1498,1500,1502,1504],{"class":49,"line":135},[47,1495,1480],{"class":65},[47,1497,1428],{"class":69},[47,1499,66],{"class":65},[47,1501,172],{"class":61},[47,1503,1288],{"class":559},[47,1505,1491],{"class":61},[47,1507,1508,1510,1512,1514,1516],{"class":49,"line":149},[47,1509,1480],{"class":65},[47,1511,1437],{"class":69},[47,1513,66],{"class":65},[47,1515,172],{"class":61},[47,1517,1518],{"class":559}," True\n",[47,1520,1521],{"class":49,"line":692},[47,1522,421],{"class":61},[47,1524,1525,1527,1529,1531],{"class":49,"line":716},[47,1526,139],{"class":138},[47,1528,117],{"class":61},[47,1530,1455],{"class":113},[47,1532,132],{"class":61},[20,1534,1535],{},"Manual creation is clearer when the values are different.",[244,1537,1539],{"id":1538},"using-a-comprehension-for-separate-mutable-values","Using a comprehension for separate mutable values",[38,1541,1543],{"className":40,"code":1542,"language":42,"meta":43,"style":43},"keys = [\"a\", \"b\", \"c\"]\ndata = {key: [] for key in keys}\nprint(data)\n",[15,1544,1545,1577,1601],{"__ignoreMap":43},[47,1546,1547,1549,1551,1553,1555,1557,1559,1561,1563,1565,1567,1569,1571,1573,1575],{"class":49,"line":50},[47,1548,54],{"class":53},[47,1550,58],{"class":57},[47,1552,62],{"class":61},[47,1554,66],{"class":65},[47,1556,210],{"class":69},[47,1558,66],{"class":65},[47,1560,75],{"class":61},[47,1562,78],{"class":65},[47,1564,854],{"class":69},[47,1566,66],{"class":65},[47,1568,75],{"class":61},[47,1570,78],{"class":65},[47,1572,863],{"class":69},[47,1574,66],{"class":65},[47,1576,95],{"class":61},[47,1578,1579,1581,1583,1585,1587,1589,1591,1593,1595,1597,1599],{"class":49,"line":98},[47,1580,872],{"class":53},[47,1582,58],{"class":57},[47,1584,1096],{"class":61},[47,1586,1099],{"class":53},[47,1588,172],{"class":61},[47,1590,1104],{"class":61},[47,1592,1108],{"class":1107},[47,1594,1111],{"class":53},[47,1596,1114],{"class":1107},[47,1598,1117],{"class":53},[47,1600,421],{"class":61},[47,1602,1603,1605,1607,1609],{"class":49,"line":135},[47,1604,139],{"class":138},[47,1606,117],{"class":61},[47,1608,898],{"class":113},[47,1610,132],{"class":61},[20,1612,1613],{},"Use:",[174,1615,1616,1621,1624],{},[177,1617,1618,1620],{},[15,1619,17],{}," when one shared simple default makes sense",[177,1622,1623],{},"Manual dictionary creation when values differ",[177,1625,1626],{},"A comprehension when each key needs its own new list or dict",[20,1628,1629,1630,110],{},"If you later want to change several values at once, you may also want to learn the ",[210,1631,1633,1634,1637],{"href":1632},"\u002Freference\u002Fpython-dictionary-update-method","Python dictionary ",[15,1635,1636],{},"update()"," method",[33,1639,1641],{"id":1640},"common-mistakes","Common mistakes",[20,1643,1644,1645,110],{},"Here are some common problems beginners run into with ",[15,1646,24],{},[244,1648,1650],{"id":1649},"using-a-mutable-default-value-by-mistake","Using a mutable default value by mistake",[38,1652,1654],{"className":40,"code":1653,"language":42,"meta":43,"style":43},"d = dict.fromkeys([\"a\", \"b\"], [])\nd[\"a\"].append(1)\nprint(d)\n",[15,1655,1656,1689,1712],{"__ignoreMap":43},[47,1657,1658,1661,1663,1665,1667,1669,1671,1673,1675,1677,1679,1681,1683,1685,1687],{"class":49,"line":50},[47,1659,1660],{"class":53},"d ",[47,1662,58],{"class":57},[47,1664,107],{"class":106},[47,1666,110],{"class":61},[47,1668,114],{"class":113},[47,1670,1258],{"class":61},[47,1672,66],{"class":65},[47,1674,210],{"class":69},[47,1676,66],{"class":65},[47,1678,75],{"class":61},[47,1680,78],{"class":65},[47,1682,854],{"class":69},[47,1684,66],{"class":65},[47,1686,959],{"class":61},[47,1688,889],{"class":61},[47,1690,1691,1694,1696,1698,1700,1702,1704,1706,1708,1710],{"class":49,"line":98},[47,1692,1693],{"class":53},"d",[47,1695,669],{"class":61},[47,1697,66],{"class":65},[47,1699,210],{"class":69},[47,1701,66],{"class":65},[47,1703,909],{"class":61},[47,1705,912],{"class":113},[47,1707,117],{"class":61},[47,1709,917],{"class":349},[47,1711,132],{"class":61},[47,1713,1714,1716,1718,1720],{"class":49,"line":135},[47,1715,139],{"class":138},[47,1717,117],{"class":61},[47,1719,1693],{"class":113},[47,1721,132],{"class":61},[20,1723,372],{},[38,1725,1727],{"className":40,"code":1726,"language":42,"meta":43,"style":43},"{'a': [1], 'b': [1]}\n",[15,1728,1729],{"__ignoreMap":43},[47,1730,1731,1733,1735,1737,1739,1741,1743,1745,1747,1749,1751,1753,1755,1757,1759],{"class":49,"line":50},[47,1732,382],{"class":61},[47,1734,385],{"class":65},[47,1736,210],{"class":69},[47,1738,385],{"class":65},[47,1740,172],{"class":61},[47,1742,62],{"class":61},[47,1744,917],{"class":349},[47,1746,959],{"class":61},[47,1748,398],{"class":65},[47,1750,854],{"class":69},[47,1752,385],{"class":65},[47,1754,172],{"class":61},[47,1756,62],{"class":61},[47,1758,917],{"class":349},[47,1760,988],{"class":61},[20,1762,1763],{},"This happens because both keys share the same list.",[20,1765,1766],{},"Use this instead:",[38,1768,1770],{"className":40,"code":1769,"language":42,"meta":43,"style":43},"keys = [\"a\", \"b\"]\nd = {key: [] for key in keys}\nprint(d)\n",[15,1771,1772,1796,1820],{"__ignoreMap":43},[47,1773,1774,1776,1778,1780,1782,1784,1786,1788,1790,1792,1794],{"class":49,"line":50},[47,1775,54],{"class":53},[47,1777,58],{"class":57},[47,1779,62],{"class":61},[47,1781,66],{"class":65},[47,1783,210],{"class":69},[47,1785,66],{"class":65},[47,1787,75],{"class":61},[47,1789,78],{"class":65},[47,1791,854],{"class":69},[47,1793,66],{"class":65},[47,1795,95],{"class":61},[47,1797,1798,1800,1802,1804,1806,1808,1810,1812,1814,1816,1818],{"class":49,"line":98},[47,1799,1660],{"class":53},[47,1801,58],{"class":57},[47,1803,1096],{"class":61},[47,1805,1099],{"class":53},[47,1807,172],{"class":61},[47,1809,1104],{"class":61},[47,1811,1108],{"class":1107},[47,1813,1111],{"class":53},[47,1815,1114],{"class":1107},[47,1817,1117],{"class":53},[47,1819,421],{"class":61},[47,1821,1822,1824,1826,1828],{"class":49,"line":135},[47,1823,139],{"class":138},[47,1825,117],{"class":61},[47,1827,1693],{"class":113},[47,1829,132],{"class":61},[244,1831,1833,1834,1836],{"id":1832},"trying-to-call-fromkeys-on-a-list","Trying to call ",[15,1835,17],{}," on a list",[20,1838,1839],{},"Wrong idea:",[38,1841,1843],{"className":40,"code":1842,"language":42,"meta":43,"style":43},"keys = [\"a\", \"b\", \"c\"]\n# keys.fromkeys(0)\n",[15,1844,1845,1877],{"__ignoreMap":43},[47,1846,1847,1849,1851,1853,1855,1857,1859,1861,1863,1865,1867,1869,1871,1873,1875],{"class":49,"line":50},[47,1848,54],{"class":53},[47,1850,58],{"class":57},[47,1852,62],{"class":61},[47,1854,66],{"class":65},[47,1856,210],{"class":69},[47,1858,66],{"class":65},[47,1860,75],{"class":61},[47,1862,78],{"class":65},[47,1864,854],{"class":69},[47,1866,66],{"class":65},[47,1868,75],{"class":61},[47,1870,78],{"class":65},[47,1872,863],{"class":69},[47,1874,66],{"class":65},[47,1876,95],{"class":61},[47,1878,1879],{"class":49,"line":98},[47,1880,1881],{"class":152},"# keys.fromkeys(0)\n",[20,1883,1884,1886,1887,1889,1890,110],{},[15,1885,17],{}," belongs to ",[15,1888,198],{},", not ",[15,1891,1892],{},"list",[20,1894,1895],{},"Correct usage:",[38,1897,1899],{"className":40,"code":1898,"language":42,"meta":43,"style":43},"keys = [\"a\", \"b\", \"c\"]\nd = dict.fromkeys(keys, 0)\nprint(d)\n",[15,1900,1901,1933,1955],{"__ignoreMap":43},[47,1902,1903,1905,1907,1909,1911,1913,1915,1917,1919,1921,1923,1925,1927,1929,1931],{"class":49,"line":50},[47,1904,54],{"class":53},[47,1906,58],{"class":57},[47,1908,62],{"class":61},[47,1910,66],{"class":65},[47,1912,210],{"class":69},[47,1914,66],{"class":65},[47,1916,75],{"class":61},[47,1918,78],{"class":65},[47,1920,854],{"class":69},[47,1922,66],{"class":65},[47,1924,75],{"class":61},[47,1926,78],{"class":65},[47,1928,863],{"class":69},[47,1930,66],{"class":65},[47,1932,95],{"class":61},[47,1934,1935,1937,1939,1941,1943,1945,1947,1949,1951,1953],{"class":49,"line":98},[47,1936,1660],{"class":53},[47,1938,58],{"class":57},[47,1940,107],{"class":106},[47,1942,110],{"class":61},[47,1944,114],{"class":113},[47,1946,117],{"class":61},[47,1948,120],{"class":113},[47,1950,75],{"class":61},[47,1952,350],{"class":349},[47,1954,132],{"class":61},[47,1956,1957,1959,1961,1963],{"class":49,"line":135},[47,1958,139],{"class":138},[47,1960,117],{"class":61},[47,1962,1693],{"class":113},[47,1964,132],{"class":61},[244,1966,1968,1969,1971],{"id":1967},"expecting-fromkeys-to-update-an-existing-dictionary","Expecting ",[15,1970,17],{}," to update an existing dictionary",[20,1973,1974,1976],{},[15,1975,24],{}," does not change an existing dictionary. It creates a new one.",[38,1978,1980],{"className":40,"code":1979,"language":42,"meta":43,"style":43},"original = {\"x\": 1}\nnew_dict = dict.fromkeys([\"a\", \"b\"], 0)\n\nprint(original)\nprint(new_dict)\n",[15,1981,1982,2005,2040,2044,2055],{"__ignoreMap":43},[47,1983,1984,1987,1989,1991,1993,1996,1998,2000,2003],{"class":49,"line":50},[47,1985,1986],{"class":53},"original ",[47,1988,58],{"class":57},[47,1990,1096],{"class":61},[47,1992,66],{"class":65},[47,1994,1995],{"class":69},"x",[47,1997,66],{"class":65},[47,1999,172],{"class":61},[47,2001,2002],{"class":349}," 1",[47,2004,421],{"class":61},[47,2006,2007,2010,2012,2014,2016,2018,2020,2022,2024,2026,2028,2030,2032,2034,2036,2038],{"class":49,"line":98},[47,2008,2009],{"class":53},"new_dict ",[47,2011,58],{"class":57},[47,2013,107],{"class":106},[47,2015,110],{"class":61},[47,2017,114],{"class":113},[47,2019,1258],{"class":61},[47,2021,66],{"class":65},[47,2023,210],{"class":69},[47,2025,66],{"class":65},[47,2027,75],{"class":61},[47,2029,78],{"class":65},[47,2031,854],{"class":69},[47,2033,66],{"class":65},[47,2035,959],{"class":61},[47,2037,350],{"class":349},[47,2039,132],{"class":61},[47,2041,2042],{"class":49,"line":135},[47,2043,358],{"emptyLinePlaceholder":357},[47,2045,2046,2048,2050,2053],{"class":49,"line":149},[47,2047,139],{"class":138},[47,2049,117],{"class":61},[47,2051,2052],{"class":113},"original",[47,2054,132],{"class":61},[47,2056,2057,2059,2061,2064],{"class":49,"line":692},[47,2058,139],{"class":138},[47,2060,117],{"class":61},[47,2062,2063],{"class":113},"new_dict",[47,2065,132],{"class":61},[20,2067,372],{},[38,2069,2071],{"className":40,"code":2070,"language":42,"meta":43,"style":43},"{'x': 1}\n{'a': 0, 'b': 0}\n",[15,2072,2073,2089],{"__ignoreMap":43},[47,2074,2075,2077,2079,2081,2083,2085,2087],{"class":49,"line":50},[47,2076,382],{"class":61},[47,2078,385],{"class":65},[47,2080,1995],{"class":69},[47,2082,385],{"class":65},[47,2084,172],{"class":61},[47,2086,2002],{"class":349},[47,2088,421],{"class":61},[47,2090,2091,2093,2095,2097,2099,2101,2103,2105,2107,2109,2111,2113,2115],{"class":49,"line":98},[47,2092,382],{"class":61},[47,2094,385],{"class":65},[47,2096,210],{"class":69},[47,2098,385],{"class":65},[47,2100,172],{"class":61},[47,2102,350],{"class":349},[47,2104,75],{"class":61},[47,2106,398],{"class":65},[47,2108,854],{"class":69},[47,2110,385],{"class":65},[47,2112,172],{"class":61},[47,2114,350],{"class":349},[47,2116,421],{"class":61},[20,2118,2119,2120,110],{},"If you want to modify an existing dictionary, see the ",[210,2121,1633,2122,1637],{"href":1632},[15,2123,1636],{},[244,2125,2127,2128],{"id":2126},"forgetting-that-the-default-value-is-none","Forgetting that the default value is ",[15,2129,269],{},[38,2131,2133],{"className":40,"code":2132,"language":42,"meta":43,"style":43},"d = dict.fromkeys([\"x\", \"y\"])\nprint(d)\n",[15,2134,2135,2167],{"__ignoreMap":43},[47,2136,2137,2139,2141,2143,2145,2147,2149,2151,2153,2155,2157,2159,2162,2164],{"class":49,"line":50},[47,2138,1660],{"class":53},[47,2140,58],{"class":57},[47,2142,107],{"class":106},[47,2144,110],{"class":61},[47,2146,114],{"class":113},[47,2148,1258],{"class":61},[47,2150,66],{"class":65},[47,2152,1995],{"class":69},[47,2154,66],{"class":65},[47,2156,75],{"class":61},[47,2158,78],{"class":65},[47,2160,2161],{"class":69},"y",[47,2163,66],{"class":65},[47,2165,2166],{"class":61},"])\n",[47,2168,2169,2171,2173,2175],{"class":49,"line":98},[47,2170,139],{"class":138},[47,2172,117],{"class":61},[47,2174,1693],{"class":113},[47,2176,132],{"class":61},[20,2178,372],{},[38,2180,2182],{"className":40,"code":2181,"language":42,"meta":43,"style":43},"{'x': None, 'y': None}\n",[15,2183,2184],{"__ignoreMap":43},[47,2185,2186,2188,2190,2192,2194,2196,2198,2200,2202,2204,2206,2208,2210],{"class":49,"line":50},[47,2187,382],{"class":61},[47,2189,385],{"class":65},[47,2191,1995],{"class":69},[47,2193,385],{"class":65},[47,2195,172],{"class":61},[47,2197,560],{"class":559},[47,2199,75],{"class":61},[47,2201,398],{"class":65},[47,2203,2161],{"class":69},[47,2205,385],{"class":65},[47,2207,172],{"class":61},[47,2209,560],{"class":559},[47,2211,421],{"class":61},[20,2213,2214,2215,110],{},"If you do not pass a second argument, every key gets ",[15,2216,269],{},[33,2218,2220],{"id":2219},"useful-checks","Useful checks",[20,2222,2223,2224,2226],{},"You can run these small examples to understand how ",[15,2225,17],{}," works.",[38,2228,2230],{"className":40,"code":2229,"language":42,"meta":43,"style":43},"print(dict.fromkeys([\"a\", \"b\"], 0))\n",[15,2231,2232],{"__ignoreMap":43},[47,2233,2234,2236,2238,2240,2242,2244,2246,2248,2250,2252,2254,2256,2258,2260,2262,2264],{"class":49,"line":50},[47,2235,139],{"class":138},[47,2237,117],{"class":61},[47,2239,198],{"class":106},[47,2241,110],{"class":61},[47,2243,114],{"class":113},[47,2245,1258],{"class":61},[47,2247,66],{"class":65},[47,2249,210],{"class":69},[47,2251,66],{"class":65},[47,2253,75],{"class":61},[47,2255,78],{"class":65},[47,2257,854],{"class":69},[47,2259,66],{"class":65},[47,2261,959],{"class":61},[47,2263,350],{"class":349},[47,2265,2266],{"class":61},"))\n",[38,2268,2269],{"className":40,"code":2132,"language":42,"meta":43,"style":43},[15,2270,2271,2301],{"__ignoreMap":43},[47,2272,2273,2275,2277,2279,2281,2283,2285,2287,2289,2291,2293,2295,2297,2299],{"class":49,"line":50},[47,2274,1660],{"class":53},[47,2276,58],{"class":57},[47,2278,107],{"class":106},[47,2280,110],{"class":61},[47,2282,114],{"class":113},[47,2284,1258],{"class":61},[47,2286,66],{"class":65},[47,2288,1995],{"class":69},[47,2290,66],{"class":65},[47,2292,75],{"class":61},[47,2294,78],{"class":65},[47,2296,2161],{"class":69},[47,2298,66],{"class":65},[47,2300,2166],{"class":61},[47,2302,2303,2305,2307,2309],{"class":49,"line":98},[47,2304,139],{"class":138},[47,2306,117],{"class":61},[47,2308,1693],{"class":113},[47,2310,132],{"class":61},[38,2312,2313],{"className":40,"code":1653,"language":42,"meta":43,"style":43},[15,2314,2315,2347,2369],{"__ignoreMap":43},[47,2316,2317,2319,2321,2323,2325,2327,2329,2331,2333,2335,2337,2339,2341,2343,2345],{"class":49,"line":50},[47,2318,1660],{"class":53},[47,2320,58],{"class":57},[47,2322,107],{"class":106},[47,2324,110],{"class":61},[47,2326,114],{"class":113},[47,2328,1258],{"class":61},[47,2330,66],{"class":65},[47,2332,210],{"class":69},[47,2334,66],{"class":65},[47,2336,75],{"class":61},[47,2338,78],{"class":65},[47,2340,854],{"class":69},[47,2342,66],{"class":65},[47,2344,959],{"class":61},[47,2346,889],{"class":61},[47,2348,2349,2351,2353,2355,2357,2359,2361,2363,2365,2367],{"class":49,"line":98},[47,2350,1693],{"class":53},[47,2352,669],{"class":61},[47,2354,66],{"class":65},[47,2356,210],{"class":69},[47,2358,66],{"class":65},[47,2360,909],{"class":61},[47,2362,912],{"class":113},[47,2364,117],{"class":61},[47,2366,917],{"class":349},[47,2368,132],{"class":61},[47,2370,2371,2373,2375,2377],{"class":49,"line":135},[47,2372,139],{"class":138},[47,2374,117],{"class":61},[47,2376,1693],{"class":113},[47,2378,132],{"class":61},[38,2380,2382],{"className":40,"code":2381,"language":42,"meta":43,"style":43},"print(type(dict.fromkeys([1, 2, 3], \"value\")))\n",[15,2383,2384],{"__ignoreMap":43},[47,2385,2386,2388,2390,2393,2395,2397,2399,2401,2403,2405,2407,2410,2412,2415,2417,2419,2421,2423],{"class":49,"line":50},[47,2387,139],{"class":138},[47,2389,117],{"class":61},[47,2391,2392],{"class":106},"type",[47,2394,117],{"class":61},[47,2396,198],{"class":106},[47,2398,110],{"class":61},[47,2400,114],{"class":113},[47,2402,1258],{"class":61},[47,2404,917],{"class":349},[47,2406,75],{"class":61},[47,2408,2409],{"class":349}," 2",[47,2411,75],{"class":61},[47,2413,2414],{"class":349}," 3",[47,2416,959],{"class":61},[47,2418,78],{"class":65},[47,2420,259],{"class":69},[47,2422,66],{"class":65},[47,2424,2425],{"class":61},")))\n",[33,2427,2429],{"id":2428},"faq","FAQ",[244,2431,2433,2434,2436],{"id":2432},"does-fromkeys-change-an-existing-dictionary","Does ",[15,2435,17],{}," change an existing dictionary?",[20,2438,2439],{},"No. It creates and returns a new dictionary.",[244,2441,2443],{"id":2442},"what-value-is-used-if-i-do-not-pass-the-second-argument","What value is used if I do not pass the second argument?",[20,2445,2446,2447,110],{},"Each key gets ",[15,2448,269],{},[244,2450,2452],{"id":2451},"can-i-use-a-list-as-the-default-value","Can I use a list as the default value?",[20,2454,2455],{},"Yes, but all keys will share the same list object.",[244,2457,2459],{"id":2458},"how-do-i-give-each-key-its-own-empty-list","How do I give each key its own empty list?",[20,2461,1050],{},[38,2463,2465],{"className":40,"code":2464,"language":42,"meta":43,"style":43},"keys = [\"a\", \"b\", \"c\"]\ndata = {key: [] for key in keys}\n",[15,2466,2467,2499],{"__ignoreMap":43},[47,2468,2469,2471,2473,2475,2477,2479,2481,2483,2485,2487,2489,2491,2493,2495,2497],{"class":49,"line":50},[47,2470,54],{"class":53},[47,2472,58],{"class":57},[47,2474,62],{"class":61},[47,2476,66],{"class":65},[47,2478,210],{"class":69},[47,2480,66],{"class":65},[47,2482,75],{"class":61},[47,2484,78],{"class":65},[47,2486,854],{"class":69},[47,2488,66],{"class":65},[47,2490,75],{"class":61},[47,2492,78],{"class":65},[47,2494,863],{"class":69},[47,2496,66],{"class":65},[47,2498,95],{"class":61},[47,2500,2501,2503,2505,2507,2509,2511,2513,2515,2517,2519,2521],{"class":49,"line":98},[47,2502,872],{"class":53},[47,2504,58],{"class":57},[47,2506,1096],{"class":61},[47,2508,1099],{"class":53},[47,2510,172],{"class":61},[47,2512,1104],{"class":61},[47,2514,1108],{"class":1107},[47,2516,1111],{"class":53},[47,2518,1114],{"class":1107},[47,2520,1117],{"class":53},[47,2522,421],{"class":61},[33,2524,2526],{"id":2525},"see-also","See also",[174,2528,2529,2534,2538,2543,2549],{},[177,2530,2531],{},[210,2532,2533],{"href":448},"Creating a dictionary in Python",[177,2535,2536],{},[210,2537,213],{"href":212},[177,2539,2540],{},[210,2541,2542],{"href":790},"How to add a key to a dictionary in Python",[177,2544,2545],{},[210,2546,1633,2547,1637],{"href":1632},[15,2548,1636],{},[177,2550,2551],{},[210,2552,1633,2554,1637],{"href":2553},"\u002Freference\u002Fpython-dictionary-copy-method",[15,2555,2556],{},"copy()",[20,2558,156,2559,2561],{},[15,2560,24],{}," when all keys should start with the same simple value. If each key needs its own separate list or dictionary, use a dictionary comprehension instead.",[2563,2564,2565],"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 .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 .sZMiF, html code.shiki .sZMiF{--shiki-light:#E2931D;--shiki-default:#005CC5;--shiki-dark:#79B8FF}html pre.shiki code .slqww, html code.shiki .slqww{--shiki-light:#6182B8;--shiki-default:#24292E;--shiki-dark:#E1E4E8}html pre.shiki code .sptTA, html code.shiki .sptTA{--shiki-light:#6182B8;--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 .srdBf, html code.shiki .srdBf{--shiki-light:#F76D47;--shiki-default:#005CC5;--shiki-dark:#79B8FF}html pre.shiki code .s39Yj, html code.shiki .s39Yj{--shiki-light:#39ADB5;--shiki-default:#005CC5;--shiki-dark:#79B8FF}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}",{"title":43,"searchDepth":98,"depth":98,"links":2567},[2568,2569,2571,2575,2576,2578,2583,2585,2592,2601,2602,2609],{"id":35,"depth":98,"text":36},{"id":163,"depth":98,"text":2570},"What dict.fromkeys() does",{"id":216,"depth":98,"text":217,"children":2572},[2573,2574],{"id":246,"depth":135,"text":247},{"id":272,"depth":135,"text":273},{"id":283,"depth":98,"text":284},{"id":452,"depth":98,"text":2577},"Using fromkeys() without a value",{"id":794,"depth":98,"text":795,"children":2579},[2580,2581,2582],{"id":827,"depth":135,"text":828},{"id":998,"depth":135,"text":999},{"id":1046,"depth":135,"text":1047},{"id":1215,"depth":98,"text":2584},"When to use fromkeys()",{"id":1381,"depth":98,"text":2586,"children":2587},"fromkeys() vs creating a dictionary manually",[2588,2590,2591],{"id":1392,"depth":135,"text":2589},"Using fromkeys()",{"id":1460,"depth":135,"text":1461},{"id":1538,"depth":135,"text":1539},{"id":1640,"depth":98,"text":1641,"children":2593},[2594,2595,2597,2599],{"id":1649,"depth":135,"text":1650},{"id":1832,"depth":135,"text":2596},"Trying to call fromkeys() on a list",{"id":1967,"depth":135,"text":2598},"Expecting fromkeys() to update an existing dictionary",{"id":2126,"depth":135,"text":2600},"Forgetting that the default value is None",{"id":2219,"depth":98,"text":2220},{"id":2428,"depth":98,"text":2429,"children":2603},[2604,2606,2607,2608],{"id":2432,"depth":135,"text":2605},"Does fromkeys() change an existing dictionary?",{"id":2442,"depth":135,"text":2443},{"id":2451,"depth":135,"text":2452},{"id":2458,"depth":135,"text":2459},{"id":2525,"depth":98,"text":2526},"Master python dictionary fromkeys method in our comprehensive Python beginner guide.","md",{},"\u002Freference\u002Fpython-dictionary-fromkeys-method",{"title":5,"description":2610},"reference\u002Fpython-dictionary-fromkeys-method","2yJ4KIc9BK_9yVeJ8MeOaa9ypdRp2WVvVsnxvO7dWyw",1777585487851]