Finding if letter = another letter in python

Question

This is in python and I'm having a little trouble finding this out, I put.

s = 'goodbye'

and I want to know if the first letter is a g. so i put

s[0] = 'g'

but i get an error, what is the right way to finding this?

Answer 1

A single = means 'assignment', and doing two == means 'compare and see if they're equal'. The difference between the two can be subtle (just a single character difference!), so make sure you don't get confused between the two

You want s[0] == 'g':

if s[0] == 'g':
    print "word starts with 'g'"

Doing s[0] = 'g' is telling Python "change the first letter of the string to 'g'". However, that fails because in Python, strings are immutable -- they can never be changed.

Answer 2

You could use the startswith(prefix) method (returns True if string starts with the prefix, otherwise returns False):

>>> s = 'hello'
>>> a = s.startswith('h')
>>> a
True