python: rstrip one exact string, respecting order

Question

Is it possible to use the python command rstrip so that it does only remove one exact string and does not take all letters separately?

I was confused w

Answer 1

Define a helper function:

def strip_suffix(s, suf):
    if s.endswith(suf):
        return s[:len(s)-len(suf)]
    return s

or use regex:

import re
suffix = ".txt"
s = re.sub(re.escape(suffix) + '$', '', s)

Answer 2

You're using wrong method. Use str.replace instead:

>>> "Boat.txt".replace(".txt", "")
'Boat'

NOTE: str.replace will replace anywhere in the string.

>>> "Boat.txt.txt".replace(".txt", "")
'Boat'

To remove the last trailing .txt only, you can use regular expression:

>>> import re
>>> re.sub(r"\.txt$", "", "Boat.txt.txt")
'Boat.txt'

If you want filename without extension, os.path.splitext is more appropriate:

>>> os.path.splitext("Boat.txt")
('Boat', '.txt')

Answer 3

In Python 3.9, as part of PEP-616, you can now use the removeprefix and removesuffix functions:

>>> "Boat.txt".removeprefix("Boat")
>>> '.txt'

>>> "Boat.txt".removesuffix(".txt")
>>> 'Boat'

Answer 4

In addition to the other excellent answers, sometimes rpartiton may also get you there (depends on the exact usecase).

>> "Boat.txt".rpartition('.txt')
('Boat', '.txt', '')

>> "Boat.txt".rpartition('.txt')[0]
'Boat'

Answer 5

This will work regardless of extension type.

# Find the rightmost period character
filename = "my file 1234.txt"

file_extension_position = filename.rindex(".")

# Substring the filename from first char up until the final period position
stripped_filename = filename[0:file_extension_position]
print("Stripped Filename: {}".format(stripped_filename))

Answer 6

>>> myfile = "file.txt"
>>> t = ""
>>> for i in myfile:
...     if i != ".":
...             t+=i
...     else:
...             break
... 
>>> t
'file'
>>> # Or You can do this
>>> import collections
>>> d = collections.deque("file.txt")
>>> while True:
...     try:
...             if "." in t:
...                     break
...             t+=d.popleft()
...     except IndexError:
...             break
...     finally:
...             filename = t[:-1]
... 
>>> filename
'file'
>>>