if else statements

[DeaD_EyE]

If you want to compare a user-input of equality, but case-insensitive, then lower the user-input and compare it only with the lower variant of the string.

...
user_input = input("Do your choice: ")

if user_input == "b" or user_input == "B":
    print("User-Input was:", user_input)
else:
    print("Got a different input")

Same logic, but shorter:

...
user_input = input("Do your choice: ")

# first user_input.lower() is evaluated, then this is compared to "b"
# the user_input itself is imutable, so user_input.lower() creates a new string with only
# lower case characters
if user_input.lower() == "b":
    # here the original user_input is used, which is not lowered
    print("User-Input was:", user_input)
else:
    print("Got a different input")