I have a string ,for example s = "-1+2-3"
I want to replace all -
to +
and all +
to -
.
what I expected is s = +1-2+3
.So I can’t just use s.replace('-','+').replace('+','-')
,because it return s=-1-2-3
,maybe a for loop can help. But I wonder if there is a pythonic way to do so?
thanks for all solutions i did a simple test for all function below
def a(s="-1+2-3"): s = re.sub('[+-]', lambda match: '-' if match[0] == '+' else '+', s) return s def b(s="-1+2-3"): PLUS = '+' MINUS = '-' swap = {ord(PLUS): ord(MINUS), ord(MINUS): ord(PLUS)} s = s.translate(swap) return s def c(s="-1+2-3"): replacements = {"+": "-", "-": "+"} return ''.join([replacements[i] if i in replacements.keys() else i for i in s]) def d(s="-1+2-3"): return s.replace('+', 'x01').replace('-', '+').replace('x01', '-') if __name__ == '__main__': a = timeit.timeit(a, number=100000) # a=0.20307550000000002 b = timeit.timeit(b, number=100000) # b=0.08596850000000006 c = timeit.timeit(c, number=100000) # c=0.12203799999999998 d = timeit.timeit(d, number=100000) # d=0.033226100000000036 print(f"{a=}n{b=}n{c=}n{d=}n")
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Answer
You can use translate (without ord
as pointed out by Barmar):
s = "-1+2-3" s.translate(str.maketrans('-+', '+-'))
Output:
'+1-2+3'