How to apply a logical operator to all elements in a python list

Question

I have a list of booleans in python. I want to AND (or OR or NOT) them and get the result. The following code works but is not very pythonic.

def apply_and(alist):  if len(alist) > 1:      return alist[0] and apply_and(alist[1:])  else:      return alist[0] 

Any suggestions on how to make it more pythonic appreciated.

Answer 1

Logical and across all elements in a_list:

all(a_list) 

Logical or across all elements in a_list:

any(a_list) 

---

If you feel creative, you can also do:

import operator def my_all(a_list):   return reduce(operator.and_, a_list, True)  def my_any(a_list):   return reduce(operator.or_, a_list, False) 

keep in mind that those aren't evaluated in short circuit, whilst the built-ins are ;-)

another funny way:

def my_all_v2(a_list):   return len(filter(None,a_list)) == len(a_list)  def my_any_v2(a_list):   return len(filter(None,a_list)) > 0 

and yet another:

def my_all_v3(a_list):   for i in a_list:     if not i:       return False   return True  def my_any_v3(a_list):   for i in a_list:     if i:       return True   return False 

and we could go on all day, but yes, the pythonic way is to use all and any :-)

By the way, Python has not tail recursion elimination, so don't try to translate LISP code directly ;-)