Python之：sys&os&time&map&sorted&iter&next&zip

'''
sys 是一个和 python 解释器密切相关的标准库
os 是一个和操作系统密切相关的标准库
'''

# -*- coding:utf-8 -*-

# import sys
#
# def multi_sum(args):
#     return sum(args)
#
# if __name__ == '__main__':
#     print(sys.argv)
#     args = sys.argv[1:]
#     result = multi_sum([float(item) for item in args])
#     print('输入了%d个参数'%len(args))
#     print('累计和为%f'%result)


# 从全路径提取路径、文件名、扩展名
# import os
# fn = 'C:\\Users\\kaibin\\AppData\\Local\\Programs\\Python\\Python37\\pythonw.exe'
# dirname, basename = os.path.split(fn)
# print(dirname)
# print(basename)
# name, ext = os.path.splitext(basename)
# print(name)
# print(ext)

# 获取当前路径下的全路径文件名
# import os
#
# print(os.getcwd())
# print(os.listdir())
# # 拼接quanlujing
# print(os.path.join(os.getcwd(),'python.exe'))

# 遍历文件夹
import os
for root, dirs, files in os.walk('C:\\Program Files\\Python37'):
    for name in files:
        print(os.path.join(root,name))
    for name in dirs:
        print(os.path.join(root,name))


# import time
# print(time.time()) # 返回当前的时间戳，也就是自1970年元旦零时至当前的秒数
#
# # time.time() 转化为 time.perf_counter()精度更高
#
# # 时间戳和日期字符串的转化
# # time.strftime()
#
# # 返回当前时间的字符串
# print(time.asctime())

# datetime 子类 datetime 和 timedelta(简单理解时间增量)

# 某个时间之前的多少时间是多少
# from datetime import datetime, timedelta
#
# dt = datetime(2019,12,2,0,0,0)
# delta = timedelta(days=2000,hours=7)
# print(dt - delta)

# 当前距离新年还有多少秒
# from datetime import datetime,timedelta
#
# now = datetime.now()
# new_year = datetime(now.year + 1, 1, 1, 0, 0, 0)
# delta = new_year - now
# print(delta.total_seconds())


# map(function,iterable,...)

# def X(v):
#     return pow(v,2)
#
# a = map(X,[1,2,3,4,5])
# print(list(a))


# sorted(iterable,key=None,reverse=False)

# a = [
#     [6,5],
#     [3,7],
#     [2,8]
# ]
#
# a1 = sorted(a,key=lambda x:x[0])
# a2 = sorted(a,key=lambda x:x[-1])
#
# print(a1,'\n',a2)

# filter(function,iterable)
# def k(v):
#     return v<=3
# list1 = list(filter(k,[4,0,3,2]))
# print(list1)
# list2 = list(filter(None,[4,0,3,2])) # None 筛选出结果不为False的值
# print(list2)

# iter()函数用于生成一个迭代器对象
# next()

# zip() 函数用于创建一个迭代器来聚合来自每个迭代对象的元素，元素按照相同的下标聚合，长度不同则忽略大于最短迭代对象长度的元素
# a = [1,2,3,4,5,6,7]
# b = [7,6,5,4,3]
# s = list(zip(a,b))
# print(s)
# for i in zip(a,b):
#     print(i)
# print("***********解压*******************")
# x,y = zip(*zip(a,b))
# print(x)
# print("我是一条分割线")
# print(y)

# quit()
# exit()

# def f(n):
#     if n > 5:
#         exit()
#     res = 1
#     for i in range(n):
#         res *= i + 1
#     return res
#
# print(f(10))