9.13. 文件和流

9.13.1. 1.stdin

import sys

print("Enter number1: ")
a = int(sys.stdin.readline())

print("Enter number2: ")
b = int(sys.stdin.readline())

c = a + b
sys.stdout.write("Result: %d " % c)

#!/usr/bin/env python
#-*- coding:utf8 -*-
# auther; 18793
# Date：2019/7/20 11:35
# filename: stdin输入.py
import sys


# stdin表示流的标准输入，通过流对象stdin读取文件hello.txt的内容
sys.stdin = open("hello.txt","r")
for line in sys.stdin.readlines():
    print(line.strip())

输出内容

test0001
test0001
test0001
test0001
test0001
test0002

9.13.2. 2.stdout将输出的内容保存到文件中

#!/usr/bin/env python
# -*- coding:utf8 -*-
# auther; 18793
# Date：2019/7/20 11:39
# filename: stdout输出到控制台.py
import sys


# 通过stdout对象重定向输出，把输出的结果保存到文件中
sys.stdout = open(r"./hello.txt", "a")
print("\n goodbye")
sys.stdout.close()

9.13.3. 3.stderr记录输出异常信息

如果hello.txt内容为空，则在error.log中记录异常信息。

如果hello.txt内容不为空，则在日志error.log文件中记录正确的信息

#!/usr/bin/env python
# -*- coding:utf8 -*-
# auther; 18793
# Date：2019/7/20 11:42
# filename: stderr记录输出异常信息.py
import sys
import time

sys.stderr = open("error.log", "a",encoding="utf-8")
f = open(r"./hello.txt", "r")
t = time.strftime("%Y-%m-%d %X", time.localtime())
context = f.read()
if context:
    sys.stderr.write(t + " " + context)
else:
    raise Exception(t + ' 异常信息')

9.13.4. 模拟Java的输入、输出流

函数FileoutputStrem()把FileinputStrem()读取的内容写入文件hello2.txt中

#!/usr/bin/env python
# -*- coding:utf8 -*-
# auther; 18793
# Date：2019/7/20 11:53
# filename: 模拟Java的输入输出流.py

def FileinputStrem(filename):
    """
    文件输入流
    :return:
    """
    try:
        f = open(filename)
        for line in f:
            for byte in line:
                yield byte
    except StopIteration as e:
        f.close()
        return


def FileoutputStrem(inputStream, filename):
    """
    文件输出流
    :return:
    """
    try:
        f = open(filename, "w")
        while True:
            byte = inputStream.__next__()
            f.write(byte)
    except StopIteration as e:
        f.close()
        return


if __name__ == '__main__':
    FileoutputStrem(FileinputStrem("hello.txt"), "hello2.txt")

9.13.5. 浏览文件属性

#!/usr/bin/env python
# -*- coding:utf8 -*-
# auther; 18793
# Date：2019/11/9 22:35
# filename: 文件属性浏览.py

def showFileProperties(path):
    """
    显示文件的属性，
    :param path: 文件夹路径
    :return:
    """
    import time, os
    for root, dirs, files in os.walk(path, True):
        print("位置：" + root)
        for filename in files:
            state = os.stat(os.path.join(root, filename))
            info = "文件名:" + filename + " "
            info = info + "\t大小:" + ("%d" % state[-4]) + " "
            t = time.strftime("%Y-%m-%d %X", time.localtime(state[-1]))
            info = info + "\t创建时间:" + t + " "
            t = time.strftime("%Y-%m-%d %X", time.localtime(state[-2]))
            info = info + "\t最后修改时间:" + t + " "
            t = time.strftime("%Y-%m-%d %X", time.localtime(state[-3]))
            info = info + "\t最后访问时间:" + t + " "
            print(info)


if __name__ == '__main__':
    path = "D:\\21-DAY-Python\\13.python文件操作/文件和流"
    showFileProperties(path)