Which is better in python?

conditional-statements, python

Solution

Case 1

From https://docs.python.org/2/library/functions.html#all

all(iterable)

Return True if all elements of the iterable are true (or if the iterable is empty). Equivalent to:

def all(iterable):
    for element in iterable:
        if not element:
            return False
    return True

This means `if a and b and c:` and `if all( (a, b, c) ):` do the same thing (duh) but `all()` involves a function call and a loop, so it's bound to be a little slower, but really, just a tiny bit.

I'd say you use `if a and b and c:` if you have only a couple variables (no more than 3) to keep it readable and `all()` if you have more.

Keep in mind: readability is almost always more important than a minor performance improvement.

`all()` and `any()` can take a list comprehension as input which is really useful.

Note: `all()` is only available in Python 2.5+

Case 2

Same as case 1, really. Because it's almost the exact same function

any(iterable)

Return True if any element of the iterable is true. If the iterable is empty, return False. Equivalent to:

def any(iterable):
    for element in iterable:
        if element:
            return True
    return False

Note: `any()` is only available in Python 2.5+

Case 3

From http://legacy.python.org/dev/peps/pep-0008/#programming-recommendations

Use is not operator rather than not ... is. While both expressions are functionally identical, the former is more readable and preferred.

You should use `if x not in a:` over `if not x in a:`, because the styleguide is holy

Problem

I have used some conditions statements in python which gives the same result. I would like to know which is better and what is the difference in performance and logic between them. Case 1: ``` if a and b and c: #some action ``` vs ``` if all( (a, b, c) ): #some action ``` Case 2: ``` if a or b or c: #some action ``` vs ``` if any( (a, b, c) ): #some action ``` Case 3: ``` if not x in a: #some action ``` vs ``` if x not in a: #some action ``` In the above cases, I would like know about the difference in performance and logic and preferred way.

Original source