"""This module contains a code example related to
Think Python, 2nd Edition
by Allen Downey
http://thinkpython2.com
Copyright 2015 Allen Downey
License: http://creativecommons.org/licenses/by/4.0/
"""
from __future__ import print_function, division
def has_duplicates(t):
"""Checks whether any element appears more than once in a sequence.
Simple version using a for loop.
t: sequence
"""
d = {}
for x in t:
if x in d:
return True
d[x] = True
return False
def has_duplicates2(t):
"""Checks whether any element appears more than once in a sequence.
Faster version using a set.
t: sequence
"""
return len(set(t)) < len(t)
if __name__ == '__main__':
t = [1, 2, 3]
print(has_duplicates(t))
t.append(1)
print(has_duplicates(t))
t = [1, 2, 3]
print(has_duplicates2(t))
t.append(1)
print(has_duplicates2(t))
