语法错误在if条件下.不等于符号突出显示

Question

当我运行此操作时，我会在" ="一部分"！="符号突出显示

的" ="一部分时获得无效的语法错误

我不认为这是每句话的语法问题，因为我尝试使用" =="符号，但我仍然遇到了相同的错误，第二个" ="符号被突出显示

def delete(line_number):
    src = "userinfo.txt"
    dest = "tempfile.txt"
    counter = 1
    with open(src, "r") as input:
        with open(dest, "w") as output: 
            for line in input:
                if counter++ != line_number:
                    output.write(line)

Answer 1

python不支持像其他语言那样的增量操作，因此您需要使用+来增加计数。

def delete(line_number):
    src = "userinfo.txt"
    dest = "tempfile.txt"
    counter = 1
    with open(src, "r") as input:
        with open(dest, "w") as output: 
            for line in input:
                counter += 1
                if counter != line_number:
                    output.write(line)

注意： counter += 1与counter = counter + 1相同。