conditional replacement within strings of pandas dataframe column

Question

Say I've got a column in my Pandas Dataframe that looks like this:

s = pd.Series(["ab-cd.", "abc", "abc-def/", "ab.cde", "abcd-"])

I would like to use this column for fuzzy matching and therefore I want to remove characters ('.' , '/' , '-') but only at the end of each string so it looks like this:

s = pd.Series(["ab-cd", "abc", "abc-def", "ab.cde", "abcd"])

So far I started out easy so instead of generating a list with characters I want removed I just repeated commands for different characters like:

if s.str[-1] == '.':
  s.str[-1].replace('.', '')

But this simply produces an error. How do I get the result I want, that is strings without characters at the end (characters in the rest of the string need to be preserved)?

Answer 1

Replace with regex will help you get the output

s.replace(r'[./-]$','',regex=True)

or with the help of apply incase looking for an alternative

s.apply(lambda x :x[:-1] if x[-1] is '.' or '-' or '/' else x) 

0      ab-cd
1        abc
2    abc-def
3     ab.cde
4       abcd
dtype: object

Answer 2

You can use str.replace with a regex:

>>> s = pd.Series(["ab-cd.", "abc", "abc-def/", "ab.cde", "abcd-"])
>>> s.str.replace("\.$|/$|\-$","")
0      ab-cd
1        abc
2    abc-def
3     ab.cde
4       abcd
dtype: object
>>> 

which can be reduced to this:

>>> s.str.replace("[./-]$","")
0      ab-cd
1        abc
2    abc-def
3     ab.cde
4       abcd
dtype: object
>>> 

Answer 3

You can use str.replace with a regular expression

s.str.replace(r'[./-]$','')

Substitute inside [./-] any characters you want to replace. $ means the match should be at the end of the string.

To replace "in-place" use Series.replace

s.replace(r'[./-]$','', inplace=True, regex=True)

Answer 4

I was able to remove characters from the end of strings in a column in a pandas DataFrame with the following line of code:

s.replace(r'[./-]$','',regex=True)

Where all entries in between brackets ( [./-] ) indicate characters to be removed and $ indicate they should be removed from the end