Python 子字符串替换

Question

我需要替换主字符串中的子字符串

mainstr='"Name":"xxx","age":"{"This":"has to","be":"replaced"}","dept":"cse"'
substr='"{"This":"has to","be":"replaced"}"'

期望的输出:

mainstr="Name:xxx","age":"checked","dept":"cse"

我尝试了以下代码:

for substr in mainstr:

    mainstr=mainstr.replace(substr,"checked")
    print "Output=",mainstr

执行时我得到了，

Output="Name:xxx","age":"{This":"has to","be":"replaced"}","dept":"cse"   

为什么 substr 没有被替换??..

Answer 1

您正在遍历字符串，但这并没有达到您的预期。迭代字符串会遍历每个字符。

您需要做的是:

mainstr = '"Name:xxx","age":"{This":"has to","be":"replaced"}","dept":"cse"'
substr = '{This":"has to","be":"replaced"}'
print "Output = ", mainstr.replace(substr, 'checked')
#                ^ The comma here is important.

注意:该代码不适用于您，因为 substr = '"{This 而不是 substr = '{This"。请注意开头的引号。