Files
python3-cookbook/cookbook/c01/p10_remove_duplicate.py
2014-09-02 13:57:50 +08:00

39 lines
836 B
Python

#!/usr/bin/env python
# -*- encoding: utf-8 -*-
"""
Topic: 消除序列重复值并保持顺序
Desc :
"""
def dedupe(items):
"""元素都是hashable"""
seen = set()
for item in items:
if item not in seen:
yield item
seen.add(item)
def dedupe2(items, key=None):
"""元素不是hashable的时候"""
seen = set()
for item in items:
val = item if key is None else key(item)
if val not in seen:
yield item
seen.add(val)
def remove_dup():
a = [1, 5, 2, 1, 9, 1, 5, 10]
print(list(dedupe(a)))
a = [{'x': 1, 'y': 2}, {'x': 1, 'y': 3}, {'x': 1, 'y': 2}, {'x': 2, 'y': 4}]
print(list(dedupe2(a, key=lambda d: (d['x'], d['y']))))
print(list(dedupe2(a, key=lambda d: d['x'])))
if __name__ == '__main__':
remove_dup()