How to delete a character from a string using Python

Posted on

Question :

How to delete a character from a string using Python

There is a string, for example. EXAMPLE.

How can I remove the middle character, i.e., M from it? I don’t need the code. I want to know:

  • Do strings in Python end in any special character?
  • Which is a better way – shifting everything right to left starting from the middle character OR creation of a new string and not copying the middle character?
Asked By: Lazer

||

Answer #1:

In Python, strings are immutable, so you have to create a new string. You have a few options of how to create the new string. If you want to remove the ‘M’ wherever it appears:

newstr = oldstr.replace("M", "")

If you want to remove the central character:

midlen = len(oldstr)/2   # //2 in python 3
newstr = oldstr[:midlen] + oldstr[midlen+1:]

You asked if strings end with a special character. No, you are thinking like a C programmer. In Python, strings are stored with their length, so any byte value, including , can appear in a string.

Answered By: Ned Batchelder

Answer #2:

This is probably the best way:

original = "EXAMPLE"
removed = original.replace("M", "")

Don’t worry about shifting characters and such. Most Python code takes place on a much higher level of abstraction.

Answered By: recursive

Answer #3:

To replace a specific position:

s = s[:pos] + s[(pos+1):]

To replace a specific character:

s = s.replace('M','')
Answered By: Eton B.

Answer #4:

Strings are immutable. But you can convert them to a list, which is mutable, and then convert the list back to a string after you’ve changed it.

s = "this is a string"

l = list(s)  # convert to list

l[1] = ""    # "delete" letter h (the item actually still exists but is empty)
l[1:2] = []  # really delete letter h (the item is actually removed from the list)
del(l[1])    # another way to delete it

p = l.index("a")  # find position of the letter "a"
del(l[p])         # delete it

s = "".join(l)  # convert back to string

You can also create a new string, as others have shown, by taking everything except the character you want from the existing string.

Answered By: kindall

Answer #5:

How can I remove the middle character, i.e., M from it?

You can’t, because strings in Python are immutable.

Do strings in Python end in any special character?

No. They are similar to lists of characters; the length of the list defines the length of the string, and no character acts as a terminator.

Which is a better way – shifting everything right to left starting from the middle character OR creation of a new string and not copying the middle character?

You cannot modify the existing string, so you must create a new one containing everything except the middle character.

Answered By: Richard Fearn

Answer #6:

Use the translate() method:

>>> s = 'EXAMPLE'
>>> s.translate(None, 'M')
'EXAPLE'

Answer #7:

def kill_char(string, n): # n = position of which character you want to remove
    begin = string[:n]    # from beginning to n (n not included)
    end = string[n+1:]    # n+1 through end of string
    return begin + end
print kill_char("EXAMPLE", 3)  # "M" removed

I have seen this somewhere here.

Answered By: user1443297

Answer #8:

UserString.MutableString

Mutable way:

import UserString

s = UserString.MutableString("EXAMPLE")

>>> type(s)
<type 'str'>

# Delete 'M'
del s[3]

# Turn it for immutable:
s = str(s)
Answered By: killown

Leave a Reply

Your email address will not be published. Required fields are marked *