python - 在 Python 中从字符串中删除子字符串

Question

我想编写一个接受 2 个输入的函数:一个字符串和一个子字符串，然后该函数将从字符串中删除那部分子字符串。

def remove_substring(s, substr):
   """(str, str) -> NoneType
Returns string without string substr

remove_substring_from_string("Im in cs", "cs")
Im in
    """
    other_s = ''
for substr in s:
    if substr in s:
        continue

我如何从这里继续？假设我的逻辑是合理的。

Answer 1

避免使用 Python 函数。

方法一

def remove_substring_from_string(s, substr):
    '''
    find start index in s of substring
    remove it by skipping over it
    '''
    i = 0
    while i < len(s) - len(substr) + 1:
        # Check if substring starts at i
        if s[i:i+len(substr)] == substr:
            break   
        i += 1
    else:
        # break not hit, so substr not found
        return s
    
    # break hit
    return s[:i] + s[i+len(substr):]

方法二

如果可以使用range函数，上面可以写得更简洁一些

def remove_substring_from_string(s, substr):
    '''
    find start index in s of substring
    remove it by skipping over it
    '''
    for i in range(len(s) - len(substr) + 1):
        if s[i:i+len(substr)] == substr:
            break
    else:
        # break not hit, so substr not found
        return s
    
    return s[:i] + s[i+len(substr):]

测试

print(remove_substring_from_string("I have nothing to declare except my genuis", " except my genuis"))
# Output: I have nothing to declare'