checking if a letter is present in a string in python

Question

How can I check if the letter "N" is present in a string. Example:

flag = False
if string contains N:
   flag = True

So flag = True if string is "CNDDDNTD" and flag = False if string is "CCGGTTT". I think re.search will work, but not sure of the options to use.

`'N' in 'CNDDDNTD'` returns True, `'N' in 'CCGGTTT'` returns False — Peter Wang, Jul 18 '16 at 18:05
You can do ``flag = "n" in string or "N" in string`` in just one line. — Sadegh Moayedizadeh, Aug 08 '23 at 14:03

Steven Rumbalski · Answer 1 · 2016-07-18T18:15:58.237

13

>>> 'N' in 'PYTHON'
True
>>> 'N' in 'STACK OVERFLOW'
False
>>> 'N' in 'python' # uppercase and lowercase are not equal
False
>>> 'N' in 'python'.upper()
True

Also, there is no need for a conditional statement when assigning to your flag. Rather than

flag = False
if 'N' in your_string:
   flag = True

do

flag = 'N' in your_string

edited Jul 18 '16 at 18:15

answered Jul 18 '16 at 18:06

Steven Rumbalski

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checking if a letter is present in a string in python

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