[{"data":1,"prerenderedAt":2086},["ShallowReactive",2],{"doc-\u002Freference\u002Fpython-dictionary-update-method":3},{"id":4,"title":5,"body":6,"description":2079,"extension":2080,"meta":2081,"navigation":682,"path":2082,"seo":2083,"stem":2084,"__hash__":2085},"content\u002Freference\u002Fpython-dictionary-update-method.md","Python Dictionary update() Method",{"type":7,"value":8,"toc":2051},"minimark",[9,19,26,29,34,170,176,183,188,191,201,204,221,224,328,331,391,399,403,406,427,432,443,446,475,478,480,541,543,564,571,576,579,590,592,711,713,766,769,781,788,794,799,802,903,905,950,953,961,964,967,1039,1042,1045,1049,1052,1127,1129,1183,1186,1189,1192,1207,1210,1222,1225,1290,1294,1301,1304,1307,1389,1391,1434,1437,1502,1504,1541,1548,1554,1559,1573,1576,1706,1708,1793,1800,1804,1809,1834,1837,1926,1929,1948,1955,1959,1967,1972,1978,1981,1988,1991,1998,2004,2011,2017,2021,2047],[10,11,13,14,18],"h1",{"id":12},"python-dictionary-update-method","Python Dictionary ",[15,16,17],"code",{},"update()"," Method",[20,21,22,23,25],"p",{},"The ",[15,24,17],{}," method changes a dictionary by adding new key-value pairs or replacing existing values.",[20,27,28],{},"Use it when you want to modify an existing dictionary instead of creating a new one.",[30,31,33],"h2",{"id":32},"quick-example","Quick example",[35,36,41],"pre",{"className":37,"code":38,"language":39,"meta":40,"style":40},"language-python shiki shiki-themes material-theme-lighter github-light github-dark","person = {\"name\": \"Ana\", \"age\": 20}\nperson.update({\"age\": 21, \"city\": \"Lima\"})\nprint(person)\n# {'name': 'Ana', 'age': 21, 'city': 'Lima'}\n","python","",[15,42,43,100,148,163],{"__ignoreMap":40},[44,45,48,52,56,60,64,68,70,73,76,79,81,84,86,89,91,93,97],"span",{"class":46,"line":47},"line",1,[44,49,51],{"class":50},"su5hD","person ",[44,53,55],{"class":54},"smGrS","=",[44,57,59],{"class":58},"sP7_E"," {",[44,61,63],{"class":62},"sjJ54","\"",[44,65,67],{"class":66},"s_sjI","name",[44,69,63],{"class":62},[44,71,72],{"class":58},":",[44,74,75],{"class":62}," \"",[44,77,78],{"class":66},"Ana",[44,80,63],{"class":62},[44,82,83],{"class":58},",",[44,85,75],{"class":62},[44,87,88],{"class":66},"age",[44,90,63],{"class":62},[44,92,72],{"class":58},[44,94,96],{"class":95},"srdBf"," 20",[44,98,99],{"class":58},"}\n",[44,101,103,106,109,113,116,118,120,122,124,127,129,131,134,136,138,140,143,145],{"class":46,"line":102},2,[44,104,105],{"class":50},"person",[44,107,108],{"class":58},".",[44,110,112],{"class":111},"slqww","update",[44,114,115],{"class":58},"({",[44,117,63],{"class":62},[44,119,88],{"class":66},[44,121,63],{"class":62},[44,123,72],{"class":58},[44,125,126],{"class":95}," 21",[44,128,83],{"class":58},[44,130,75],{"class":62},[44,132,133],{"class":66},"city",[44,135,63],{"class":62},[44,137,72],{"class":58},[44,139,75],{"class":62},[44,141,142],{"class":66},"Lima",[44,144,63],{"class":62},[44,146,147],{"class":58},"})\n",[44,149,151,155,158,160],{"class":46,"line":150},3,[44,152,154],{"class":153},"sptTA","print",[44,156,157],{"class":58},"(",[44,159,105],{"class":111},[44,161,162],{"class":58},")\n",[44,164,166],{"class":46,"line":165},4,[44,167,169],{"class":168},"sutJx","# {'name': 'Ana', 'age': 21, 'city': 'Lima'}\n",[20,171,172,173,175],{},"Use ",[15,174,17],{}," to add new keys or overwrite existing keys from another dictionary or iterable of key-value pairs.",[30,177,179,180,182],{"id":178},"what-update-does","What ",[15,181,17],{}," does",[20,184,185,187],{},[15,186,17],{}," modifies the original dictionary in place.",[20,189,190],{},"It can do two main things:",[192,193,194,198],"ul",{},[195,196,197],"li",{},"Add new key-value pairs",[195,199,200],{},"Replace values for keys that already exist",[20,202,203],{},"Important things to know:",[192,205,206,209,212,218],{},[195,207,208],{},"It changes the dictionary directly",[195,210,211],{},"It does not sort the dictionary",[195,213,214,215],{},"It returns ",[15,216,217],{},"None",[195,219,220],{},"You should not assign its result to a new variable",[20,222,223],{},"Example:",[35,225,227],{"className":37,"code":226,"language":39,"meta":40,"style":40},"student = {\"name\": \"Mira\", \"grade\": \"B\"}\nstudent.update({\"grade\": \"A\", \"city\": \"Quito\"})\nprint(student)\n",[15,228,229,273,318],{"__ignoreMap":40},[44,230,231,234,236,238,240,242,244,246,248,251,253,255,257,260,262,264,266,269,271],{"class":46,"line":47},[44,232,233],{"class":50},"student ",[44,235,55],{"class":54},[44,237,59],{"class":58},[44,239,63],{"class":62},[44,241,67],{"class":66},[44,243,63],{"class":62},[44,245,72],{"class":58},[44,247,75],{"class":62},[44,249,250],{"class":66},"Mira",[44,252,63],{"class":62},[44,254,83],{"class":58},[44,256,75],{"class":62},[44,258,259],{"class":66},"grade",[44,261,63],{"class":62},[44,263,72],{"class":58},[44,265,75],{"class":62},[44,267,268],{"class":66},"B",[44,270,63],{"class":62},[44,272,99],{"class":58},[44,274,275,278,280,282,284,286,288,290,292,294,297,299,301,303,305,307,309,311,314,316],{"class":46,"line":102},[44,276,277],{"class":50},"student",[44,279,108],{"class":58},[44,281,112],{"class":111},[44,283,115],{"class":58},[44,285,63],{"class":62},[44,287,259],{"class":66},[44,289,63],{"class":62},[44,291,72],{"class":58},[44,293,75],{"class":62},[44,295,296],{"class":66},"A",[44,298,63],{"class":62},[44,300,83],{"class":58},[44,302,75],{"class":62},[44,304,133],{"class":66},[44,306,63],{"class":62},[44,308,72],{"class":58},[44,310,75],{"class":62},[44,312,313],{"class":66},"Quito",[44,315,63],{"class":62},[44,317,147],{"class":58},[44,319,320,322,324,326],{"class":46,"line":150},[44,321,154],{"class":153},[44,323,157],{"class":58},[44,325,277],{"class":111},[44,327,162],{"class":58},[20,329,330],{},"Output:",[35,332,334],{"className":37,"code":333,"language":39,"meta":40,"style":40},"{'name': 'Mira', 'grade': 'A', 'city': 'Quito'}\n",[15,335,336],{"__ignoreMap":40},[44,337,338,341,344,346,348,350,353,355,357,359,361,363,365,367,369,371,373,375,377,379,381,383,385,387,389],{"class":46,"line":47},[44,339,340],{"class":58},"{",[44,342,343],{"class":62},"'",[44,345,67],{"class":66},[44,347,343],{"class":62},[44,349,72],{"class":58},[44,351,352],{"class":62}," '",[44,354,250],{"class":66},[44,356,343],{"class":62},[44,358,83],{"class":58},[44,360,352],{"class":62},[44,362,259],{"class":66},[44,364,343],{"class":62},[44,366,72],{"class":58},[44,368,352],{"class":62},[44,370,296],{"class":66},[44,372,343],{"class":62},[44,374,83],{"class":58},[44,376,352],{"class":62},[44,378,133],{"class":66},[44,380,343],{"class":62},[44,382,72],{"class":58},[44,384,352],{"class":62},[44,386,313],{"class":66},[44,388,343],{"class":62},[44,390,99],{"class":58},[20,392,393,394,108],{},"If you are new to dictionaries, see ",[395,396,398],"a",{"href":397},"\u002Freference\u002Fpython-dictionary-creating-a-dictionary\u002F","how to create a dictionary in Python",[30,400,402],{"id":401},"basic-syntax","Basic syntax",[20,404,405],{},"The basic form is:",[35,407,409],{"className":37,"code":408,"language":39,"meta":40,"style":40},"dictionary.update(other)\n",[15,410,411],{"__ignoreMap":40},[44,412,413,416,418,420,422,425],{"class":46,"line":47},[44,414,415],{"class":50},"dictionary",[44,417,108],{"class":58},[44,419,112],{"class":111},[44,421,157],{"class":58},[44,423,424],{"class":111},"other",[44,426,162],{"class":58},[20,428,429,431],{},[15,430,424],{}," can be:",[192,433,434,437,440],{},[195,435,436],{},"Another dictionary",[195,438,439],{},"An iterable of key-value pairs",[195,441,442],{},"Keyword arguments",[20,444,445],{},"You can also use:",[35,447,449],{"className":37,"code":448,"language":39,"meta":40,"style":40},"dictionary.update(name=\"Sam\")\n",[15,450,451],{"__ignoreMap":40},[44,452,453,455,457,459,461,464,466,468,471,473],{"class":46,"line":47},[44,454,415],{"class":50},[44,456,108],{"class":58},[44,458,112],{"class":111},[44,460,157],{"class":58},[44,462,67],{"class":463},"s99_P",[44,465,55],{"class":54},[44,467,63],{"class":62},[44,469,470],{"class":66},"Sam",[44,472,63],{"class":62},[44,474,162],{"class":58},[20,476,477],{},"If the same key appears more than once, the last value wins.",[20,479,223],{},[35,481,483],{"className":37,"code":482,"language":39,"meta":40,"style":40},"data = {\"a\": 1}\ndata.update({\"a\": 10})\nprint(data)\n",[15,484,485,507,531],{"__ignoreMap":40},[44,486,487,490,492,494,496,498,500,502,505],{"class":46,"line":47},[44,488,489],{"class":50},"data ",[44,491,55],{"class":54},[44,493,59],{"class":58},[44,495,63],{"class":62},[44,497,395],{"class":66},[44,499,63],{"class":62},[44,501,72],{"class":58},[44,503,504],{"class":95}," 1",[44,506,99],{"class":58},[44,508,509,512,514,516,518,520,522,524,526,529],{"class":46,"line":102},[44,510,511],{"class":50},"data",[44,513,108],{"class":58},[44,515,112],{"class":111},[44,517,115],{"class":58},[44,519,63],{"class":62},[44,521,395],{"class":66},[44,523,63],{"class":62},[44,525,72],{"class":58},[44,527,528],{"class":95}," 10",[44,530,147],{"class":58},[44,532,533,535,537,539],{"class":46,"line":150},[44,534,154],{"class":153},[44,536,157],{"class":58},[44,538,511],{"class":111},[44,540,162],{"class":58},[20,542,330],{},[35,544,546],{"className":37,"code":545,"language":39,"meta":40,"style":40},"{'a': 10}\n",[15,547,548],{"__ignoreMap":40},[44,549,550,552,554,556,558,560,562],{"class":46,"line":47},[44,551,340],{"class":58},[44,553,343],{"class":62},[44,555,395],{"class":66},[44,557,343],{"class":62},[44,559,72],{"class":58},[44,561,528],{"class":95},[44,563,99],{"class":58},[30,565,567,568,570],{"id":566},"using-update-with-another-dictionary","Using ",[15,569,17],{}," with another dictionary",[20,572,573,574,108],{},"This is the most common use of ",[15,575,17],{},[20,577,578],{},"It is useful when:",[192,580,581,584,587],{},[195,582,583],{},"Merging small dictionaries",[195,585,586],{},"Adding extra settings",[195,588,589],{},"Updating stored data",[20,591,223],{},[35,593,595],{"className":37,"code":594,"language":39,"meta":40,"style":40},"settings = {\"theme\": \"light\", \"font_size\": 12}\nnew_settings = {\"font_size\": 14, \"language\": \"en\"}\n\nsettings.update(new_settings)\nprint(settings)\n",[15,596,597,638,678,684,700],{"__ignoreMap":40},[44,598,599,602,604,606,608,611,613,615,617,620,622,624,626,629,631,633,636],{"class":46,"line":47},[44,600,601],{"class":50},"settings ",[44,603,55],{"class":54},[44,605,59],{"class":58},[44,607,63],{"class":62},[44,609,610],{"class":66},"theme",[44,612,63],{"class":62},[44,614,72],{"class":58},[44,616,75],{"class":62},[44,618,619],{"class":66},"light",[44,621,63],{"class":62},[44,623,83],{"class":58},[44,625,75],{"class":62},[44,627,628],{"class":66},"font_size",[44,630,63],{"class":62},[44,632,72],{"class":58},[44,634,635],{"class":95}," 12",[44,637,99],{"class":58},[44,639,640,643,645,647,649,651,653,655,658,660,662,665,667,669,671,674,676],{"class":46,"line":102},[44,641,642],{"class":50},"new_settings ",[44,644,55],{"class":54},[44,646,59],{"class":58},[44,648,63],{"class":62},[44,650,628],{"class":66},[44,652,63],{"class":62},[44,654,72],{"class":58},[44,656,657],{"class":95}," 14",[44,659,83],{"class":58},[44,661,75],{"class":62},[44,663,664],{"class":66},"language",[44,666,63],{"class":62},[44,668,72],{"class":58},[44,670,75],{"class":62},[44,672,673],{"class":66},"en",[44,675,63],{"class":62},[44,677,99],{"class":58},[44,679,680],{"class":46,"line":150},[44,681,683],{"emptyLinePlaceholder":682},true,"\n",[44,685,686,689,691,693,695,698],{"class":46,"line":165},[44,687,688],{"class":50},"settings",[44,690,108],{"class":58},[44,692,112],{"class":111},[44,694,157],{"class":58},[44,696,697],{"class":111},"new_settings",[44,699,162],{"class":58},[44,701,703,705,707,709],{"class":46,"line":702},5,[44,704,154],{"class":153},[44,706,157],{"class":58},[44,708,688],{"class":111},[44,710,162],{"class":58},[20,712,330],{},[35,714,716],{"className":37,"code":715,"language":39,"meta":40,"style":40},"{'theme': 'light', 'font_size': 14, 'language': 'en'}\n",[15,717,718],{"__ignoreMap":40},[44,719,720,722,724,726,728,730,732,734,736,738,740,742,744,746,748,750,752,754,756,758,760,762,764],{"class":46,"line":47},[44,721,340],{"class":58},[44,723,343],{"class":62},[44,725,610],{"class":66},[44,727,343],{"class":62},[44,729,72],{"class":58},[44,731,352],{"class":62},[44,733,619],{"class":66},[44,735,343],{"class":62},[44,737,83],{"class":58},[44,739,352],{"class":62},[44,741,628],{"class":66},[44,743,343],{"class":62},[44,745,72],{"class":58},[44,747,657],{"class":95},[44,749,83],{"class":58},[44,751,352],{"class":62},[44,753,664],{"class":66},[44,755,343],{"class":62},[44,757,72],{"class":58},[44,759,352],{"class":62},[44,761,673],{"class":66},[44,763,343],{"class":62},[44,765,99],{"class":58},[20,767,768],{},"What happened here:",[192,770,771,776],{},[195,772,773,775],{},[15,774,628],{}," already existed, so its value was replaced",[195,777,778,780],{},[15,779,664],{}," did not exist, so it was added",[20,782,783,784,108],{},"If you want a task-focused guide, see ",[395,785,787],{"href":786},"\u002Fhow-to\u002Fhow-to-merge-dictionaries-in-python\u002F","how to merge dictionaries in Python",[30,789,567,791,793],{"id":790},"using-update-with-key-value-pairs",[15,792,17],{}," with key-value pairs",[20,795,796,798],{},[15,797,17],{}," also works with iterables that contain pairs.",[20,800,801],{},"For example, you can pass a list of tuples:",[35,803,805],{"className":37,"code":804,"language":39,"meta":40,"style":40},"scores = {\"math\": 90}\npairs = [(\"science\", 85), (\"english\", 88)]\n\nscores.update(pairs)\nprint(scores)\n",[15,806,807,830,873,877,893],{"__ignoreMap":40},[44,808,809,812,814,816,818,821,823,825,828],{"class":46,"line":47},[44,810,811],{"class":50},"scores ",[44,813,55],{"class":54},[44,815,59],{"class":58},[44,817,63],{"class":62},[44,819,820],{"class":66},"math",[44,822,63],{"class":62},[44,824,72],{"class":58},[44,826,827],{"class":95}," 90",[44,829,99],{"class":58},[44,831,832,835,837,840,842,845,847,849,852,855,858,860,863,865,867,870],{"class":46,"line":102},[44,833,834],{"class":50},"pairs ",[44,836,55],{"class":54},[44,838,839],{"class":58}," [(",[44,841,63],{"class":62},[44,843,844],{"class":66},"science",[44,846,63],{"class":62},[44,848,83],{"class":58},[44,850,851],{"class":95}," 85",[44,853,854],{"class":58},"),",[44,856,857],{"class":58}," (",[44,859,63],{"class":62},[44,861,862],{"class":66},"english",[44,864,63],{"class":62},[44,866,83],{"class":58},[44,868,869],{"class":95}," 88",[44,871,872],{"class":58},")]\n",[44,874,875],{"class":46,"line":150},[44,876,683],{"emptyLinePlaceholder":682},[44,878,879,882,884,886,888,891],{"class":46,"line":165},[44,880,881],{"class":50},"scores",[44,883,108],{"class":58},[44,885,112],{"class":111},[44,887,157],{"class":58},[44,889,890],{"class":111},"pairs",[44,892,162],{"class":58},[44,894,895,897,899,901],{"class":46,"line":702},[44,896,154],{"class":153},[44,898,157],{"class":58},[44,900,881],{"class":111},[44,902,162],{"class":58},[20,904,330],{},[35,906,908],{"className":37,"code":907,"language":39,"meta":40,"style":40},"{'math': 90, 'science': 85, 'english': 88}\n",[15,909,910],{"__ignoreMap":40},[44,911,912,914,916,918,920,922,924,926,928,930,932,934,936,938,940,942,944,946,948],{"class":46,"line":47},[44,913,340],{"class":58},[44,915,343],{"class":62},[44,917,820],{"class":66},[44,919,343],{"class":62},[44,921,72],{"class":58},[44,923,827],{"class":95},[44,925,83],{"class":58},[44,927,352],{"class":62},[44,929,844],{"class":66},[44,931,343],{"class":62},[44,933,72],{"class":58},[44,935,851],{"class":95},[44,937,83],{"class":58},[44,939,352],{"class":62},[44,941,862],{"class":66},[44,943,343],{"class":62},[44,945,72],{"class":58},[44,947,869],{"class":95},[44,949,99],{"class":58},[20,951,952],{},"Each item must contain exactly two values:",[192,954,955,958],{},[195,956,957],{},"The key",[195,959,960],{},"The value",[20,962,963],{},"Bad structure will raise an error.",[20,965,966],{},"Example of incorrect data:",[35,968,970],{"className":37,"code":969,"language":39,"meta":40,"style":40},"data = {\"a\": 1}\nbad_pairs = [(\"b\", 2, 3)]\n\ndata.update(bad_pairs)\n",[15,971,972,992,1020,1024],{"__ignoreMap":40},[44,973,974,976,978,980,982,984,986,988,990],{"class":46,"line":47},[44,975,489],{"class":50},[44,977,55],{"class":54},[44,979,59],{"class":58},[44,981,63],{"class":62},[44,983,395],{"class":66},[44,985,63],{"class":62},[44,987,72],{"class":58},[44,989,504],{"class":95},[44,991,99],{"class":58},[44,993,994,997,999,1001,1003,1006,1008,1010,1013,1015,1018],{"class":46,"line":102},[44,995,996],{"class":50},"bad_pairs ",[44,998,55],{"class":54},[44,1000,839],{"class":58},[44,1002,63],{"class":62},[44,1004,1005],{"class":66},"b",[44,1007,63],{"class":62},[44,1009,83],{"class":58},[44,1011,1012],{"class":95}," 2",[44,1014,83],{"class":58},[44,1016,1017],{"class":95}," 3",[44,1019,872],{"class":58},[44,1021,1022],{"class":46,"line":150},[44,1023,683],{"emptyLinePlaceholder":682},[44,1025,1026,1028,1030,1032,1034,1037],{"class":46,"line":165},[44,1027,511],{"class":50},[44,1029,108],{"class":58},[44,1031,112],{"class":111},[44,1033,157],{"class":58},[44,1035,1036],{"class":111},"bad_pairs",[44,1038,162],{"class":58},[20,1040,1041],{},"This causes an error because each item must be a pair.",[20,1043,1044],{},"This form is useful when you have simple data that needs to become dictionary entries.",[30,1046,1048],{"id":1047},"using-keyword-arguments","Using keyword arguments",[20,1050,1051],{},"You can also pass key-value pairs as keyword arguments:",[35,1053,1055],{"className":37,"code":1054,"language":39,"meta":40,"style":40},"user = {\"name\": \"Leo\"}\nuser.update(age=25, city=\"Madrid\")\nprint(user)\n",[15,1056,1057,1083,1117],{"__ignoreMap":40},[44,1058,1059,1062,1064,1066,1068,1070,1072,1074,1076,1079,1081],{"class":46,"line":47},[44,1060,1061],{"class":50},"user ",[44,1063,55],{"class":54},[44,1065,59],{"class":58},[44,1067,63],{"class":62},[44,1069,67],{"class":66},[44,1071,63],{"class":62},[44,1073,72],{"class":58},[44,1075,75],{"class":62},[44,1077,1078],{"class":66},"Leo",[44,1080,63],{"class":62},[44,1082,99],{"class":58},[44,1084,1085,1088,1090,1092,1094,1096,1098,1101,1103,1106,1108,1110,1113,1115],{"class":46,"line":102},[44,1086,1087],{"class":50},"user",[44,1089,108],{"class":58},[44,1091,112],{"class":111},[44,1093,157],{"class":58},[44,1095,88],{"class":463},[44,1097,55],{"class":54},[44,1099,1100],{"class":95},"25",[44,1102,83],{"class":58},[44,1104,1105],{"class":463}," city",[44,1107,55],{"class":54},[44,1109,63],{"class":62},[44,1111,1112],{"class":66},"Madrid",[44,1114,63],{"class":62},[44,1116,162],{"class":58},[44,1118,1119,1121,1123,1125],{"class":46,"line":150},[44,1120,154],{"class":153},[44,1122,157],{"class":58},[44,1124,1087],{"class":111},[44,1126,162],{"class":58},[20,1128,330],{},[35,1130,1132],{"className":37,"code":1131,"language":39,"meta":40,"style":40},"{'name': 'Leo', 'age': 25, 'city': 'Madrid'}\n",[15,1133,1134],{"__ignoreMap":40},[44,1135,1136,1138,1140,1142,1144,1146,1148,1150,1152,1154,1156,1158,1160,1162,1165,1167,1169,1171,1173,1175,1177,1179,1181],{"class":46,"line":47},[44,1137,340],{"class":58},[44,1139,343],{"class":62},[44,1141,67],{"class":66},[44,1143,343],{"class":62},[44,1145,72],{"class":58},[44,1147,352],{"class":62},[44,1149,1078],{"class":66},[44,1151,343],{"class":62},[44,1153,83],{"class":58},[44,1155,352],{"class":62},[44,1157,88],{"class":66},[44,1159,343],{"class":62},[44,1161,72],{"class":58},[44,1163,1164],{"class":95}," 25",[44,1166,83],{"class":58},[44,1168,352],{"class":62},[44,1170,133],{"class":66},[44,1172,343],{"class":62},[44,1174,72],{"class":58},[44,1176,352],{"class":62},[44,1178,1112],{"class":66},[44,1180,343],{"class":62},[44,1182,99],{"class":58},[20,1184,1185],{},"This is convenient for simple string keys.",[20,1187,1188],{},"But there is one limit: keys must be valid Python identifiers.",[20,1190,1191],{},"These work:",[192,1193,1194,1198,1202],{},[195,1195,1196],{},[15,1197,88],{},[195,1199,1200],{},[15,1201,133],{},[195,1203,1204],{},[15,1205,1206],{},"first_name",[20,1208,1209],{},"These do not work as keyword arguments:",[192,1211,1212,1217],{},[195,1213,1214],{},[15,1215,1216],{},"\"first name\"",[195,1218,1219],{},[15,1220,1221],{},"\"user-id\"",[20,1223,1224],{},"For keys like that, use a dictionary instead:",[35,1226,1228],{"className":37,"code":1227,"language":39,"meta":40,"style":40},"user = {}\nuser.update({\"first name\": \"Leo\", \"user-id\": 1001})\nprint(user)\n",[15,1229,1230,1239,1280],{"__ignoreMap":40},[44,1231,1232,1234,1236],{"class":46,"line":47},[44,1233,1061],{"class":50},[44,1235,55],{"class":54},[44,1237,1238],{"class":58}," {}\n",[44,1240,1241,1243,1245,1247,1249,1251,1254,1256,1258,1260,1262,1264,1266,1268,1271,1273,1275,1278],{"class":46,"line":102},[44,1242,1087],{"class":50},[44,1244,108],{"class":58},[44,1246,112],{"class":111},[44,1248,115],{"class":58},[44,1250,63],{"class":62},[44,1252,1253],{"class":66},"first name",[44,1255,63],{"class":62},[44,1257,72],{"class":58},[44,1259,75],{"class":62},[44,1261,1078],{"class":66},[44,1263,63],{"class":62},[44,1265,83],{"class":58},[44,1267,75],{"class":62},[44,1269,1270],{"class":66},"user-id",[44,1272,63],{"class":62},[44,1274,72],{"class":58},[44,1276,1277],{"class":95}," 1001",[44,1279,147],{"class":58},[44,1281,1282,1284,1286,1288],{"class":46,"line":150},[44,1283,154],{"class":153},[44,1285,157],{"class":58},[44,1287,1087],{"class":111},[44,1289,162],{"class":58},[30,1291,1293],{"id":1292},"return-value","Return value",[20,1295,1296,1298,1299,108],{},[15,1297,17],{}," returns ",[15,1300,217],{},[20,1302,1303],{},"This is one of the most common beginner mistakes.",[20,1305,1306],{},"Incorrect:",[35,1308,1310],{"className":37,"code":1309,"language":39,"meta":40,"style":40},"person = {\"name\": \"Ana\"}\nresult = person.update({\"age\": 20})\n\nprint(result)\nprint(person)\n",[15,1311,1312,1336,1364,1368,1379],{"__ignoreMap":40},[44,1313,1314,1316,1318,1320,1322,1324,1326,1328,1330,1332,1334],{"class":46,"line":47},[44,1315,51],{"class":50},[44,1317,55],{"class":54},[44,1319,59],{"class":58},[44,1321,63],{"class":62},[44,1323,67],{"class":66},[44,1325,63],{"class":62},[44,1327,72],{"class":58},[44,1329,75],{"class":62},[44,1331,78],{"class":66},[44,1333,63],{"class":62},[44,1335,99],{"class":58},[44,1337,1338,1341,1343,1346,1348,1350,1352,1354,1356,1358,1360,1362],{"class":46,"line":102},[44,1339,1340],{"class":50},"result ",[44,1342,55],{"class":54},[44,1344,1345],{"class":50}," person",[44,1347,108],{"class":58},[44,1349,112],{"class":111},[44,1351,115],{"class":58},[44,1353,63],{"class":62},[44,1355,88],{"class":66},[44,1357,63],{"class":62},[44,1359,72],{"class":58},[44,1361,96],{"class":95},[44,1363,147],{"class":58},[44,1365,1366],{"class":46,"line":150},[44,1367,683],{"emptyLinePlaceholder":682},[44,1369,1370,1372,1374,1377],{"class":46,"line":165},[44,1371,154],{"class":153},[44,1373,157],{"class":58},[44,1375,1376],{"class":111},"result",[44,1378,162],{"class":58},[44,1380,1381,1383,1385,1387],{"class":46,"line":702},[44,1382,154],{"class":153},[44,1384,157],{"class":58},[44,1386,105],{"class":111},[44,1388,162],{"class":58},[20,1390,330],{},[35,1392,1394],{"className":37,"code":1393,"language":39,"meta":40,"style":40},"None\n{'name': 'Ana', 'age': 20}\n",[15,1395,1396,1402],{"__ignoreMap":40},[44,1397,1398],{"class":46,"line":47},[44,1399,1401],{"class":1400},"s39Yj","None\n",[44,1403,1404,1406,1408,1410,1412,1414,1416,1418,1420,1422,1424,1426,1428,1430,1432],{"class":46,"line":102},[44,1405,340],{"class":58},[44,1407,343],{"class":62},[44,1409,67],{"class":66},[44,1411,343],{"class":62},[44,1413,72],{"class":58},[44,1415,352],{"class":62},[44,1417,78],{"class":66},[44,1419,343],{"class":62},[44,1421,83],{"class":58},[44,1423,352],{"class":62},[44,1425,88],{"class":66},[44,1427,343],{"class":62},[44,1429,72],{"class":58},[44,1431,96],{"class":95},[44,1433,99],{"class":58},[20,1435,1436],{},"Correct:",[35,1438,1440],{"className":37,"code":1439,"language":39,"meta":40,"style":40},"person = {\"name\": \"Ana\"}\nperson.update({\"age\": 20})\n\nprint(person)\n",[15,1441,1442,1466,1488,1492],{"__ignoreMap":40},[44,1443,1444,1446,1448,1450,1452,1454,1456,1458,1460,1462,1464],{"class":46,"line":47},[44,1445,51],{"class":50},[44,1447,55],{"class":54},[44,1449,59],{"class":58},[44,1451,63],{"class":62},[44,1453,67],{"class":66},[44,1455,63],{"class":62},[44,1457,72],{"class":58},[44,1459,75],{"class":62},[44,1461,78],{"class":66},[44,1463,63],{"class":62},[44,1465,99],{"class":58},[44,1467,1468,1470,1472,1474,1476,1478,1480,1482,1484,1486],{"class":46,"line":102},[44,1469,105],{"class":50},[44,1471,108],{"class":58},[44,1473,112],{"class":111},[44,1475,115],{"class":58},[44,1477,63],{"class":62},[44,1479,88],{"class":66},[44,1481,63],{"class":62},[44,1483,72],{"class":58},[44,1485,96],{"class":95},[44,1487,147],{"class":58},[44,1489,1490],{"class":46,"line":150},[44,1491,683],{"emptyLinePlaceholder":682},[44,1493,1494,1496,1498,1500],{"class":46,"line":165},[44,1495,154],{"class":153},[44,1497,157],{"class":58},[44,1499,105],{"class":111},[44,1501,162],{"class":58},[20,1503,330],{},[35,1505,1507],{"className":37,"code":1506,"language":39,"meta":40,"style":40},"{'name': 'Ana', 'age': 20}\n",[15,1508,1509],{"__ignoreMap":40},[44,1510,1511,1513,1515,1517,1519,1521,1523,1525,1527,1529,1531,1533,1535,1537,1539],{"class":46,"line":47},[44,1512,340],{"class":58},[44,1514,343],{"class":62},[44,1516,67],{"class":66},[44,1518,343],{"class":62},[44,1520,72],{"class":58},[44,1522,352],{"class":62},[44,1524,78],{"class":66},[44,1526,343],{"class":62},[44,1528,83],{"class":58},[44,1530,352],{"class":62},[44,1532,88],{"class":66},[44,1534,343],{"class":62},[44,1536,72],{"class":58},[44,1538,96],{"class":95},[44,1540,99],{"class":58},[20,1542,1543,1544,108],{},"If you only want to add or change one key, see ",[395,1545,1547],{"href":1546},"\u002Fhow-to\u002Fhow-to-add-a-key-to-a-dictionary-in-python\u002F","how to add a key to a dictionary in Python",[30,1549,1551,1552],{"id":1550},"when-to-use-update","When to use ",[15,1553,17],{},[20,1555,172,1556,1558],{},[15,1557,17],{}," when:",[192,1560,1561,1564,1567,1570],{},[195,1562,1563],{},"You want to modify an existing dictionary",[195,1565,1566],{},"You want to add several keys at once",[195,1568,1569],{},"You want to merge settings or user data",[195,1571,1572],{},"Overwriting old values is acceptable",[20,1574,1575],{},"If you want to keep the original dictionary unchanged, make a copy first:",[35,1577,1579],{"className":37,"code":1578,"language":39,"meta":40,"style":40},"original = {\"name\": \"Ana\", \"age\": 20}\nupdated = original.copy()\n\nupdated.update({\"age\": 21, \"city\": \"Lima\"})\n\nprint(original)\nprint(updated)\n",[15,1580,1581,1618,1636,1640,1679,1683,1695],{"__ignoreMap":40},[44,1582,1583,1586,1588,1590,1592,1594,1596,1598,1600,1602,1604,1606,1608,1610,1612,1614,1616],{"class":46,"line":47},[44,1584,1585],{"class":50},"original ",[44,1587,55],{"class":54},[44,1589,59],{"class":58},[44,1591,63],{"class":62},[44,1593,67],{"class":66},[44,1595,63],{"class":62},[44,1597,72],{"class":58},[44,1599,75],{"class":62},[44,1601,78],{"class":66},[44,1603,63],{"class":62},[44,1605,83],{"class":58},[44,1607,75],{"class":62},[44,1609,88],{"class":66},[44,1611,63],{"class":62},[44,1613,72],{"class":58},[44,1615,96],{"class":95},[44,1617,99],{"class":58},[44,1619,1620,1623,1625,1628,1630,1633],{"class":46,"line":102},[44,1621,1622],{"class":50},"updated ",[44,1624,55],{"class":54},[44,1626,1627],{"class":50}," original",[44,1629,108],{"class":58},[44,1631,1632],{"class":111},"copy",[44,1634,1635],{"class":58},"()\n",[44,1637,1638],{"class":46,"line":150},[44,1639,683],{"emptyLinePlaceholder":682},[44,1641,1642,1645,1647,1649,1651,1653,1655,1657,1659,1661,1663,1665,1667,1669,1671,1673,1675,1677],{"class":46,"line":165},[44,1643,1644],{"class":50},"updated",[44,1646,108],{"class":58},[44,1648,112],{"class":111},[44,1650,115],{"class":58},[44,1652,63],{"class":62},[44,1654,88],{"class":66},[44,1656,63],{"class":62},[44,1658,72],{"class":58},[44,1660,126],{"class":95},[44,1662,83],{"class":58},[44,1664,75],{"class":62},[44,1666,133],{"class":66},[44,1668,63],{"class":62},[44,1670,72],{"class":58},[44,1672,75],{"class":62},[44,1674,142],{"class":66},[44,1676,63],{"class":62},[44,1678,147],{"class":58},[44,1680,1681],{"class":46,"line":702},[44,1682,683],{"emptyLinePlaceholder":682},[44,1684,1686,1688,1690,1693],{"class":46,"line":1685},6,[44,1687,154],{"class":153},[44,1689,157],{"class":58},[44,1691,1692],{"class":111},"original",[44,1694,162],{"class":58},[44,1696,1698,1700,1702,1704],{"class":46,"line":1697},7,[44,1699,154],{"class":153},[44,1701,157],{"class":58},[44,1703,1644],{"class":111},[44,1705,162],{"class":58},[20,1707,330],{},[35,1709,1711],{"className":37,"code":1710,"language":39,"meta":40,"style":40},"{'name': 'Ana', 'age': 20}\n{'name': 'Ana', 'age': 21, 'city': 'Lima'}\n",[15,1712,1713,1745],{"__ignoreMap":40},[44,1714,1715,1717,1719,1721,1723,1725,1727,1729,1731,1733,1735,1737,1739,1741,1743],{"class":46,"line":47},[44,1716,340],{"class":58},[44,1718,343],{"class":62},[44,1720,67],{"class":66},[44,1722,343],{"class":62},[44,1724,72],{"class":58},[44,1726,352],{"class":62},[44,1728,78],{"class":66},[44,1730,343],{"class":62},[44,1732,83],{"class":58},[44,1734,352],{"class":62},[44,1736,88],{"class":66},[44,1738,343],{"class":62},[44,1740,72],{"class":58},[44,1742,96],{"class":95},[44,1744,99],{"class":58},[44,1746,1747,1749,1751,1753,1755,1757,1759,1761,1763,1765,1767,1769,1771,1773,1775,1777,1779,1781,1783,1785,1787,1789,1791],{"class":46,"line":102},[44,1748,340],{"class":58},[44,1750,343],{"class":62},[44,1752,67],{"class":66},[44,1754,343],{"class":62},[44,1756,72],{"class":58},[44,1758,352],{"class":62},[44,1760,78],{"class":66},[44,1762,343],{"class":62},[44,1764,83],{"class":58},[44,1766,352],{"class":62},[44,1768,88],{"class":66},[44,1770,343],{"class":62},[44,1772,72],{"class":58},[44,1774,126],{"class":95},[44,1776,83],{"class":58},[44,1778,352],{"class":62},[44,1780,133],{"class":66},[44,1782,343],{"class":62},[44,1784,72],{"class":58},[44,1786,352],{"class":62},[44,1788,142],{"class":66},[44,1790,343],{"class":62},[44,1792,99],{"class":58},[20,1794,1795,1796,108],{},"After updating a dictionary, you may also want to learn ",[395,1797,1799],{"href":1798},"\u002Fhow-to\u002Fhow-to-access-values-in-a-dictionary-in-python\u002F","how to access values in a dictionary in Python",[30,1801,1803],{"id":1802},"common-mistakes","Common mistakes",[20,1805,1806,1807,72],{},"Here are the most common problems beginners run into with ",[15,1808,17],{},[192,1810,1811,1819,1825,1828,1831],{},[195,1812,1813,1814,1816,1817],{},"Assigning the result of ",[15,1815,17],{}," to a variable and getting ",[15,1818,217],{},[195,1820,1821,1822,1824],{},"Expecting ",[15,1823,17],{}," to return a new dictionary",[195,1826,1827],{},"Passing items that are not key-value pairs",[195,1829,1830],{},"Using keyword arguments for keys that are not valid identifiers",[195,1832,1833],{},"Overwriting existing values by mistake",[20,1835,1836],{},"Useful debugging checks:",[35,1838,1840],{"className":37,"code":1839,"language":39,"meta":40,"style":40},"print(my_dict)\nprint(type(data))\nprint(list(data))\nprint(my_dict.get('key'))\nhelp(dict.update)\n",[15,1841,1842,1853,1870,1885,1909],{"__ignoreMap":40},[44,1843,1844,1846,1848,1851],{"class":46,"line":47},[44,1845,154],{"class":153},[44,1847,157],{"class":58},[44,1849,1850],{"class":111},"my_dict",[44,1852,162],{"class":58},[44,1854,1855,1857,1859,1863,1865,1867],{"class":46,"line":102},[44,1856,154],{"class":153},[44,1858,157],{"class":58},[44,1860,1862],{"class":1861},"sZMiF","type",[44,1864,157],{"class":58},[44,1866,511],{"class":111},[44,1868,1869],{"class":58},"))\n",[44,1871,1872,1874,1876,1879,1881,1883],{"class":46,"line":150},[44,1873,154],{"class":153},[44,1875,157],{"class":58},[44,1877,1878],{"class":1861},"list",[44,1880,157],{"class":58},[44,1882,511],{"class":111},[44,1884,1869],{"class":58},[44,1886,1887,1889,1891,1893,1895,1898,1900,1902,1905,1907],{"class":46,"line":165},[44,1888,154],{"class":153},[44,1890,157],{"class":58},[44,1892,1850],{"class":111},[44,1894,108],{"class":58},[44,1896,1897],{"class":111},"get",[44,1899,157],{"class":58},[44,1901,343],{"class":62},[44,1903,1904],{"class":66},"key",[44,1906,343],{"class":62},[44,1908,1869],{"class":58},[44,1910,1911,1914,1916,1919,1921,1924],{"class":46,"line":702},[44,1912,1913],{"class":153},"help",[44,1915,157],{"class":58},[44,1917,1918],{"class":1861},"dict",[44,1920,108],{"class":58},[44,1922,112],{"class":1923},"skxfh",[44,1925,162],{"class":58},[20,1927,1928],{},"These can help you check:",[192,1930,1931,1934,1939,1942,1945],{},[195,1932,1933],{},"What your dictionary currently contains",[195,1935,1936,1937],{},"What type of data you are passing to ",[15,1938,17],{},[195,1940,1941],{},"Whether your input really contains pairs",[195,1943,1944],{},"Whether a key exists",[195,1946,1947],{},"The built-in method help text",[20,1949,1950,1951,108],{},"If you are trying to read a missing key after updating, you may also run into ",[395,1952,1954],{"href":1953},"\u002Ferrors\u002Fkeyerror-in-python-causes-and-fixes\u002F","KeyError in Python: causes and fixes",[30,1956,1958],{"id":1957},"faq","FAQ",[1960,1961,1963,1964,1966],"h3",{"id":1962},"does-update-return-a-new-dictionary","Does ",[15,1965,17],{}," return a new dictionary?",[20,1968,1969,1970,108],{},"No. It changes the original dictionary and returns ",[15,1971,217],{},[1960,1973,1963,1975,1977],{"id":1974},"does-update-overwrite-existing-keys",[15,1976,17],{}," overwrite existing keys?",[20,1979,1980],{},"Yes. If a key already exists, its value is replaced.",[1960,1982,1984,1985,1987],{"id":1983},"can-update-add-new-keys","Can ",[15,1986,17],{}," add new keys?",[20,1989,1990],{},"Yes. Missing keys are added to the dictionary.",[1960,1992,1994,1995,1997],{"id":1993},"can-i-use-update-with-a-list","Can I use ",[15,1996,17],{}," with a list?",[20,1999,2000,2001,108],{},"Yes, if the list contains key-value pairs like ",[15,2002,2003],{},"[('a', 1), ('b', 2)]",[1960,2005,2007,2008,2010],{"id":2006},"what-is-the-difference-between-update-and-assigning-one-key","What is the difference between ",[15,2009,17],{}," and assigning one key?",[20,2012,2013,2014,2016],{},"Single assignment changes one key. ",[15,2015,17],{}," can change many keys at once.",[30,2018,2020],{"id":2019},"see-also","See also",[192,2022,2023,2028,2033,2038,2043],{},[195,2024,2025],{},[395,2026,2027],{"href":397},"How to create a dictionary in Python",[195,2029,2030],{},[395,2031,2032],{"href":1546},"How to add a key to a dictionary in Python",[195,2034,2035],{},[395,2036,2037],{"href":786},"How to merge dictionaries in Python",[195,2039,2040],{},[395,2041,2042],{"href":1798},"How to access values in a dictionary in Python",[195,2044,2045],{},[395,2046,1954],{"href":1953},[2048,2049,2050],"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 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