Pythonic way to apply a list of functions?

Question

I'm still new to python and I was wondering if there was a way to simplify this function into something close to a one-liner:

filters = [lambda x: is_big(x), lambda x: is_wide(x), lambda x: is_gray(x)]
def filter(input):
    for func in filters:
        if(not func(input)):
            return False
        else:
            continue
    return True

Assume the functions in the filters list return booleans. Basically is there any way I can do something like all(apply input to each filter) ?

Answer 1

all(func(input) for func in filters)

Answer 2

是的，您可以使用all() ：

result = all(f(input) for f in filters)

Answer 3

Here's a list comprehension to get filtered output from your input:

filtered = [x for x in input if all(f(x) for f in filters)]

You could also use the built in filter:

complete_filter = lambda x: all(f(x) for f in filters)
filtered = filter(complete_filter, input)

On a side note (not sure what others mean by the fact that all doesn't short circuit). See below:

def f():
    print "in f"
    return True

def g():
    print "in g"
    return False

def h():
    print "in h"
    return True

filters = [f, g, h]
print all(fn() for fn in filters)

This prints

in f
in g
False
>>>