python中的无限while循环

Question

No matter what I do, I can't get this while loop to work; unless i hardcode the value in.

count = 0
value = raw_input('How many?')
print value
while (count <= value):
        print "a"
        count= count + 1

At first I tried using a command line argument, using sys.argv[1] for value but I got the same problem. This seems so simple, yet I cannot for the life of me figure out what I'm doing wrong.

Answer 1

Ensure that value is an integer,

while (count <= int(value)):
    count= count + 1

By default raw_input is a string, and for every integer n and every string s we have n<s is True (!), hence your loop (without the int ) never breaks.

Note: In Python 3 comparing string and integers will give a TypeError: unorderable types: str() < int() , which is probably more "expected" behaviour.

Answer 2

Convert your input to an integer first

value = int(raw_input('How many?'))
print value

Answer 3

By the way, if you really want to get your statement to be value times printed change condition from

count <= int(value)

to

count < int(value)

or start count from 1