Is there any way to do variable assignments directly inside a while(<here>) loop in Python?

Question

Is there any way to do this in python? I.e. have the variable assignment return the assigned value and compare that to an empty string, directly in the while loop. No biggie if it isn't possible, just to used to doing it in php.

while((name = raw_input("Name: ")) != ''):
    names.append(name)

What I'm trying to do is identical to this in functionality:

names = []
while(True):
    name = raw_input("Name: ")
    if (name == ''):
        break
    names.append(name)

Answer 1

No, sorry. It's a FAQ though explained here:

http://www.python.org/doc/faq/general/#why-can-t-i-use-an-assignment-in-an-expression

Answer 2

No. The python solution is to turn raw_input into a generator (return the data to process with yield instead of return) and then use the for loop:

names = []
for name in raw_input("Name: "):
    names.append(name)

or, even shorter,

names = list(raw_input("Name: "))

Complete code:

def raw_input(x):
    results = ['a1','b2','c3']
    for s in results:
        yield s

names = []
for name in raw_input("Name: "):
    names.append(name)

print names
names = list(raw_input("Name: "))
print names

This prints:

['a1', 'b2', 'c3']
['a1', 'b2', 'c3']

From the comments, I now realize that raw_input() is a method defined by Python, so you need to wrap it:

def wrapper(s):
    while True:
        result = raw_input(s)
        if result = '': break
        yield s

which means we're back to square one but with more complex code. So if you need to wrap an existing method, you need to use nosklo's approach.

Answer 3

from functools import partial

for name in iter(partial(raw_input, 'Name:'), ''):
    do_something_with(name)

or if you want a list:

>>> names = list(iter(partial(raw_input, 'Name: '), ''))
Name: nosklo
Name: Andreas
Name: Aaron
Name: Phil
Name: 
>>> names
['nosklo', 'Andreas', 'Aaron', 'Phil']