python "incrementing" a character string?

Question

I know in java, if you have a char variable, you could do the following:

char a = 'a'
a = a + 1
System.out.println(a)

This would print 'b'. I don't know the exact name of what this is, but is there any way to do this in python?

In Java, a `char` value is essentially the same as an unsigned 16-bit integer. So, incrementing it is really just incrementing it. However, Python does not treat characters interchangeably with integers. — Greg Hewgill, Nov 14 '10 at 19:29
To elaborate on what Greg said, how would you increment "I am a string"? Because that's what a 'char' is in Python: a string that happens to have length 1. — aaronasterling, Nov 14 '10 at 19:35
Possible duplicate of [Python: How can I increment a char?](http://stackoverflow.com/questions/2156892/python-how-can-i-increment-a-char) — outis, Feb 14 '16 at 00:58

Vincent Savard · Accepted Answer · 2010-11-14T19:28:30.480

14

You could use ord and chr :

print(chr(ord('a')+1))
# b

More information about ord and chr.

edited Nov 14 '10 at 19:28

answered Nov 14 '10 at 19:22

Vincent Savard

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score 5 · Answer 2 · edited Nov 14 '10 at 19:40

5

As an alternative,

if you actually need to move over the alphabet like in your example, you can use string.lowercase and iterate over that:

from string import lowercase

for a in lowercase:
    print a

see http://docs.python.org/library/string.html#string-constants for more

edited Nov 14 '10 at 19:40

Greg Hewgill

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answered Nov 14 '10 at 19:30

Carson Myers

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score 1 · Answer 3 · answered Sep 26 '15 at 06:32

Above solutions wont work when char is z and you increment that by 1 or 2,

Example: if you increment z by incr (lets say incr = 2 or 3) then (chr(ord('z')+incr)) does not give you incremented value because ascii value goes out of range.

for generic way you have to do this

i = a to z any character
incr = no. of increment
#if letter is lowercase
asci = ord(i)
if (asci >= 97) & (asci <= 122):            
  asci += incr
  # for increment case
  if asci > 122 :
    asci = asci%122 + 96
    # for decrement case
    if asci < 97:
      asci += 26
    print chr(asci)

it will work for increment or decrement both.

same can be done for uppercase letter, only asci value will be changed.

python "incrementing" a character string?

3 Answers3