# the while loop needs a True condition, here x < 10 to run
# and will stop running on False, when x goes to 10 or above
x = 0
while x < 10:
    # do something with x
    print x
    # increment x by 1, same as x = x + 1
    x += 1

print

# 'while True' would be an endless loop, so you need to break it
# with a break condition (an if statement), stops when x is 10 or higher
x = 0
while True:
    # do something with x
    print x
    x += 1
    if x >= 10:
        break

"""
output in either case -->
0
1
2
3
4
5
6
7
8
9
"""

# whittle down a string with while:
s = "internets"
# string s is True until it's empty
while s: 
    print s
    # each time around remove one char from the end
    s = s[:-1]

"""
output -->
internets
internet
interne
intern
inter
inte
int
in
i
"""

flag1 = False
flag2 = False
while not (flag1 or flag2):
    for i in range(10):
        print i
        if i == 4:
            flag1 = True
            break
        elif i == 6:
            flag2 = True
            break

def myfunc(i, j):
    print i, j
    if i == j == 1:
        raise StopIteration
    
try:
    while True:
        for i in range(10):
            for j in range(10):
                myfunc(i, j)
except StopIteration:
    pass

def count_to_9(x):
    # do something with x
    print x
    x += 1
    if x >= 10:
        return
    count_to_9(x)

# start the loop at zero
count_to_9(0)

"""
output -->
0
1
2
3
4
5
6
7
8
9
"""