如何检查一个或多个特定字符是否为字符串？

Question

I want to check if two strings contain "\\n" or "\\r" using just one if statement not two, and is there any way to do this or must I use a for loop?

I tried tweaking the if statement in many ways but it seems like I just cant get it right, so must I use a for loop or two if statements?

def singleline_diff_format(line1, line2, idx):
    """
    Inputs:
      line1 - first single line string
      line2 - second single line string
      idx   - index at which to indicate difference
    Output:
      Returns a three line formatted string showing the location
      of the first difference between line1 and line2.

      If either input line contains a newline or carriage return,
      then returns an empty string.

      If idx is not a valid index, then returns an empty string.
     """
    equals = "=" * (idx)
    min_length = min(len(line1), len(line2))

    if "\n" or "\r" in line1 or line2:
        return ""
    else:
        return line1 +  "\n{}^".format(equals) + "\n" + line2 

print(singleline_diff_format("abcd", "abed", 2))
print(singleline_diff_format("abcd \nhey man", "abed", 2))    
print(singleline_diff_format("abcd", "abed", 5))

I expect

abcd

==^

abed

abcd

hey man

==^

abed

abcd

=====^

abed

But I just get empty strings which means that the if statement isn't working properly.

Answer 1

You could use any :

if any(char in line for char in ('\n',  '\r') for line in (line1, line2)):
    ....

This will be True if any of the 4 conditions '\\n' in line1 , '\\n' in line2 , '\\r' in line1 , '\\r' in line2 is `True - and is much more compact...

Answer 2

Your logic isn't doing what you intend and when you do match, you are returning an empty string. if "\\n" or "\\r" in line1 or line2: return ""

Try: if ("\\n" or "\\r") in (line1 or line2): return f'{line1}\\n=\\n{line2}'