Try to find the number 26 with 2,3,4,5 and the four basic operations (+,-,/,*)

Twentysix.py

import math

# Try to find the number 26 with 2,3,4,5 and the four basic operations (+,-,/,*)

def all_perms(str):
    if len(str) <= 1:
        yield str
    else:
        for perm in all_perms(str[1:]):
            for i in range(len(perm)+1):
                yield perm[:i] + str[0:1] + perm[i:]

def calc(expr):
    return eval(expr, dict(__builtins__ = None), {})

def calculate(p):
    try:
        res = calc(" ".join(p))
        if res == 26:
            print " ".join(p)
    except:
        pass

def main():
    numbers = ['2.', '3.', '4.', '5.']
    all_signs = [['+', '-', '/', '(', ')'], ['+', '-', '*', '(', ')'], ['+', '*', '/', '(', ')'], ['-', '*', '/', '(', ')']]

    for signs in all_signs:
        d = numbers + signs
        for p in all_perms(d):
            if p[0] in ['2.', '3.', '4.', '5.', '(']:
                calculate(p)
            
if __name__ == "__main__":
    main()