3 回答
TA貢獻(xiàn)1856條經(jīng)驗(yàn) 獲得超11個(gè)贊
該with語句自動(dòng)關(guān)閉文件。當(dāng)您嘗試通過語句外的 DictReader 訪問數(shù)據(jù)時(shí)with,DictReader 無法訪問已關(guān)閉的文件,因此您會(huì)得到 IOError。
您可以通過在從函數(shù)返回之前將文件中的行收集到列表中來解決這個(gè)問題:
def myfunc():
fileName: some file on my system
with open(fileName) as csv1:
dataDict = csv.DictReader(csv1, delimiter=',')
list_of_dicts = list(datadict)
return list_of_dicts
TA貢獻(xiàn)1856條經(jīng)驗(yàn) 獲得超17個(gè)贊
DictReader 是懶惰的。實(shí)際上把它變成一個(gè)列表并返回它,這樣文件就可以在它仍然打開的時(shí)候被讀取。
def myfunc():
fileName: some file on my system
with open(fileName) as csv:
return list(csv.DictReader(csv, delimiter=','))
TA貢獻(xiàn)1883條經(jīng)驗(yàn) 獲得超3個(gè)贊
你可以將它復(fù)制到另一個(gè)變量中并返回它......
def myfunc():
fileName: some file on my system
mydict = {}
with open(fileName) as f:
for row in csv.DictReader(f, delimiter=','):
mydict[row['first_column']] = row['second_column'] + row['third_column']
return mydict
用 csv 中的列名替換列名。
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