В слове поменять местами части до и после дефиса

#s='кошки-мышки'
s=input('s=')
s1=s2=''
f=False
for c in s:
    if c=='-': f=True
    elif not f:
        s1+=c
    else: s2+=c
print(s2+'-'+s1)

s = input()
s1 = ''
s2 = ''
flag = True
for i in range(len(s)):
    if s[i] == '-':
        flag = False
    if flag:
        s1 += s[i]
    elif s[i] != '-':
        s2 += s[i]
    elif s[i] == '-':
        s3 = s[i]
print(s2 + s3 + s1)

s = input()
s1 = ''
i = 0
while s[i] != '-':
    s1 += s[i]
    i += 1
s1 = '-' + s1
i = len(s)-1
while s[i] != '-':
    s1 = s[i] + s1
    i -= 1
print(s1)

s = list(input('->'))
L = R = ''
i = 0
while s[i] != '-':
    L += s[i]
    i += 1
i = -1
while s[i] != '-':
    R = s[i] + R
    i -= 1
print(R + '-' + L)

import re
s = input()
print(re.sub(r'^([^-]+)-(.+)$', r'\2-\1', s))

s = 'кошки-мышки'#input('=> ')
 
r = l = []
for i in range(len(s)):
    if s[i] != '-':
        l += [s[i]]
    else:
        r = l
        l = []
l += ['-'] + r
print(''.join(l))

>>> s = "abc-def"
>>> x = s.index("-")
>>> a = s[:x]
>>> b = s[x + 1:]
>>> ss = "%s-%s" % (b, a)
>>> print(ss)
def-abc
>>>

dir(str)