guess_your_number.py

low = 1
high = 100
playing = True

print('Guess your number game')
input('Now think of a number from 1 to 100, then press Enter')

print("""
All you have to do is answer to my guess
'c' if my guess is correct
's' if my guess is 'S'maller than your number
'l' if my guess is 'L'arger than your number
""")

while playing:
    mid = (low + high) // 2
    answer = input('Is {0} your number? '.format(mid))
    if answer.lower() == 'c':
        print('I knew it!')
        playing = False
    elif answer.lower() == 's':
        low = mid
    elif answer.lower() == 'l':
        high = mid