Remove all characters from a string before/until a specific string variable occurs in Python-CodePudding

I have a string, and I want to remove all the characters before another string variable using .split(). Does anyone know how to do it?

'5 5 20-5 5.4 50/2' is my string, '20' is my variable, and I want to remove everything before 20.

CodePudding user response：

Try this:

s1 = '5 5 20-5 5.4 50/2'
s2 = '20'

new_s1 = s2   s1.split(s2, 1)[1]

Result:

'20-5 5.4 50/2'

This relies on the fact that s2 is in fact contained in s1.

Just be aware that using str.split() is definitely not the best approach here.

CodePudding user response：

Using .partition():

before, sep, after = '5 5 20-5 5.4 50/2'.partition('20')

print(before) # -> '5 5 '

print(sep) # -> '20'

print(after) # -> '-5 5.4 50/2'

CodePudding user response：

Another solution using string slicing and the index function:

s1 = '5 5 20-5 5.4 50/2'
s2 = '20'

# returns the resulting string or s1 if s2 not found in s1
print(s1[s1.index(s2):] if s2 in s1 else s1)

# result:
20-5 5.4 50/2