python中有大于但不是函数吗？

Question

I have this code I'm just playing with, As I'm new to python, which is this:

a = 0
while a < 10:
    a = a + 1
    print("A is Less than 10")

I want to add some more code that says: If a is more than 10 but less than 20, print this:
I tried:

a = 0
while a < 10:
    a = a + 1
    print("A is Less than 10")
while a < 20:
    a = a + 1
    print("A is More than 10, but less than 20.")

But all that does is print "A is more than 10, but less than 20"
Basically, is there a "Less than but greater than" function in python? I'm running version 3 by the way.

Answer 1

while 10 < a < 20:
    whatever

This doesn't work in most languages, but Python supports it. Note that you should probably be using a for loop:

for a in range(11, 20):
    whatever

or if you just want to test a single number rather than looping, use an if :

if 10 < a < 20:
    whatever

Be careful with the boundary conditions. When your first loop ends, a is set to 10 . (In fact, it's already set to 10 when you print the last "less than 10" message.) If you immediately check whether it's greater than 10, you'll find it's not.

Answer 2

In Python you can even write

while 10 < a < 20:
    do_smth()