如何修复python中不一致的return语句? [英] How to fix inconsistent return statement in python?

问题描述

我是python的新手，我有一个项目，我正在一个具有两个函数的小项目上，其中第一个返回第一次在字符串中发现差异的索引.下一个函数会执行此操作，但会在字符串列表中.现在，由于我是一个业余爱好者，我使用了过多的if和else语句，这导致了太多的return语句，尤其是在第二个函数中，并且出现了错误[R1710:inconsistent-return-statements].我该如何解决它，有人可以给我清晰的示例来介绍更好的代码吗?很抱歉这个问题这么久.

I am new to python and i have this project I am working on a small project with two functions where the first returns the index of the first time a difference is spotted in a string. The next function does that but in a list of strings. Now, due to my being an amateur, i have used an excessive amount of if and else statements which resulted in too many return statements especially in the second function, and i get the error [R1710: inconsistent-return-statements]. How do i fix it and can anybody give me clear examples to better pieces of code? Sorry for the question being so long.

IDENTICAL = -1
def singleline_diff(line1, line2):
    """
    Inputs:
        line1 - first single line string
        line2 - second single line string
    Output:
        Returns the index where the first difference between
        line1 and line2 occurs.

        Returns IDENTICAL if the two lines are the same.
    """
    len1 = len(line1)
    len2 = len(line2)
    minimum_length = min(len1, len2)

    if len1 != len2:
        if minimum_length == 0:
            return 0
        for idx in range(minimum_length):
            if line1[idx] == line2[idx]:
                pass
            else:
                return idx
        return idx + 1

    for idx in range(len1):
        if line1[idx] == line2[idx]:
            pass
        else:
            return idx
    return IDENTICAL

def multiline_diff(lines1, lines2):
    """
    Inputs:
      lines1 - list of single line strings
      lines2 - list of single line strings
    Output:
      Returns a tuple containing the line number (starting from 0) and
      the index in that line where the first difference between lines1
      and lines2 occurs.

      Returns (IDENTICAL, IDENTICAL) if the two lists are the same.
    """
    line_no = singleline_diff(lines1, lines2)

    len_lines1, len_lines2 = len(lines1), len(lines2)

    if len_lines1 == len_lines2:

        if (len_lines1 or len_lines2) == 0:
            if len_lines1 == len_lines2:
                return (IDENTICAL, IDENTICAL)
            else:
                idx = singleline_diff(lines1[line_no], lines2[line_no])
                return (line_no, idx)

        else:
            idx = singleline_diff(lines1[line_no], lines2[line_no])

            if line_no == IDENTICAL:
                return (IDENTICAL, IDENTICAL)
            elif line_no != IDENTICAL:
                return (line_no, idx)

    else:
        return (line_no, 0)

推荐答案

在此处查看代码:

if len_lines1 == len_lines2:
    return (IDENTICAL, IDENTICAL)
else:
    idx = singleline_diff(lines1[line_no], lines2[line_no])
    return (line_no, idx)

您可能已经写了类似上面的内容:

You could have written the above thing like:

if len_lines1 == len_lines2:
    return (IDENTICAL, IDENTICAL)
idx = singleline_diff(lines1[line_no], lines2[line_no])
return (line_no, idx)

您只是不需要else块来返回此表达式，因为如果控件没有进入if块，则这部分代码将自动被调用.希望对您有所帮助.

You just don't need an else block to return this expression as this part of code will automatically be called if the control doesn't go into if block. Hope it helps.

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