l = [1, 2, 3, 4]
s = "Abcde"

#mutability
l[0] = 0 #this works because lists are mutable
s[0] = "a" #this throws an error because strings are immutable
s = "a" + s[1:]

#for loops are good for executing some code for every element
#in a list or for every character in a string
"""
#loop over lists
for elt in l:
    print elt

#loop over strings
for char in s:
    print char
"""

#given l, print whether elt is divisible by 2
"""
for elt in l:
    if elt % 2 == 0:
        print "divisible by 2"
    else:
        print "not divisible by 2"
"""

#for loops are also good for when you know exactly how many times
#you want to execute a block of code using the range function
#examples: range(10) = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
#          range(1, 5) = [1, 2, 3, 4]
#          range(5, 0, -1) = [5, 4, 3, 2, 1]
"""
#loops with range
l = []
for i in range(10):
    l.append(i + 2)
print l

for i in range(5):
    print i
"""

#while loops are used when you want to execute a block of code
#until a particular condition is true

"""
x = 10
while x > 0:
    # do something
    print x
    x = x - 1 #x -= 1
"""

valid_inputs = ["rock", "paper", "scissors"]
#player1 = raw_input("rock, paper, or scissors? ")

#while input is invalid:
#   ask again
#when code is valid, play RPS

"""

while player1 not in in valid_inputs:
    #ask again
        player1 = raw_input("rock, paper, or scissors? ")
else:
    #play rps
    print "RPS code here"
"""