How to downcase the first character of a string?

Question

There is a function to capitalize a string, I would like to be able to change the first character of a string to be sure it will be lowercase.

How can I do that in P

Answer 1

I'd write it this way:

def first_lower(s):
    if s == "":
        return s
    return s[0].lower() + s[1:]

This has the (relative) merit that it will throw an error if you inadvertently pass it something that isn't a string, like None or an empty list.

Answer 2

s = "Bobby tables"
s = s[0].lower() + s[1:]

Answer 3

def first_lower(s):
   if len(s) == 0:
      return s
   else:
      return s[0].lower() + s[1:]

print first_lower("HELLO")  # Prints "hELLO"
print first_lower("")       # Doesn't crash  :-)

Answer 4

Interestingly, none of these answers does exactly the opposite of capitalize(). For example, capitalize('abC') returns Abc rather than AbC. If you want the opposite of capitalize(), you need something like:

def uncapitalize(s):
  if len(s) > 0:
    s = s[0].lower() + s[1:].upper()
  return s

Answer 5

No need to handle special cases (and I think the symmetry is more Pythonic):

def uncapitalize(s):
    return s[:1].lower() + s[1:].upper()

Answer 6

This duplicate post lead me here.

If you've a list of strings like the one shown below

l = ['SentMessage', 'DeliverySucceeded', 'DeliveryFailed']

Then, to convert the first letter of all items in the list, you can use

l = [x[0].lower() + x[1:] for x in l]

Output

['sentMessage', 'deliverySucceeded', 'deliveryFailed']