python 3 : Change one character of item in list

Question

我有一个这样的列表:

['ID|number1|number2|+|name|location','ID2|number3|number4|-|name2|location2']

该列表是从字典生成的，并包含字典的键。我想改变第一个'|'变成一个“=”。

我试过这个:

keyList=[]
for item in finalDict.keys():
    keyList.append(item)

z=0
for item in keyList:
    for letter in item:
        if letter=='|':
            z+=1
            if z==1:
                letter.replace('|', '=')

但我没有得到错误或我想要的输出

Actual output:
    ['ID|number1|number2|+|name|location','ID2|number3|number4|-|name2|location2']


Desired output:
    ['ID=number1|number2|+|name|location','ID2=number3|number4|-|name2|location2']

Answer 1

to change the first '|' into a '='

简单来说:

keyList = ['ID|number1|number2|+|name|location','ID2|number3|number4|-|name2|location2']
result = [k.replace('|', '=', 1) for k in keyList]

print(result)

输出:

['ID=number1|number2|+|name|location', 'ID2=number3|number4|-|name2|location2']

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• str.replace(old, new[, count]) - 如果可选参数 count 是 给定，只有第一个出现的次数被替换。