1 python 常用函数

1.1 排序函数

原地排序 nums.sort()
不改变原列表有返回值 new = sorted(nums)

import functools
# 一维数组排序
nums = [2, 1, 3, 4, 5]


def compare_udf(x, y):
    # x - y 升序
    # y - x 降序
    return x - y 



# # python2
nums.sort(cmp=compare_udf)
# # python3
nums.sort(key=functools.cmp_to_key(compare_udf))
print(nums)

nums = [(264.0, 8, 0), (199.0, 10, 1), (230.0, 10, 2), (199.0, 9, 3)]
# 基础排序 按照一维升序排列，按照二维降序排列
new = sorted(nums, key=lambda x: (x[0], -x[1]))
print(new)

# 自定义排序
import functools


def comp(x, y):
    if x[0] != y[0]:
        return x[0] - y[0]
    else:
        return y[1] - x[1]


new = sorted(nums, key=functools.cmp_to_key(comp))
print(new)