python_文件读写详解

# !/usr/bin/env python
# -*-coding:UTF-8-*-

# data = open('yesterday', encoding='UTF-8').read()
# f = open('yesterday', 'r', encoding='UTF-8')     # f是文件句柄
# data = f.read()
# data_2 = f.read()
#
# print(data)
# print('----------------data-----------------')

# f = open('yesterday1', 'w', encoding='UTF-8')
# f.write('我爱北京天安门！\n')
# f.write('天安门上太阳升。')
# print(f)

# f = open('yesterday1', 'a', encoding='UTF-8')
# f.write('\n我爱北京天安门！\n')
# f.write('天安门上太阳升。')
# print(f)/

# f = open('yesterday', 'a', encoding='utf-8')
# for i in range(5):
#     print(f.readline())

# 效率较低，一次性全部读取到内存中
# for index, line in enumerate(f.readlines()):
#     if index == 4:
#         print('---------我是分割线---------');
#         continue
#     print(line.strip())

# 高效率，一次仅仅读取保存一行内容，当读取下一行内容时自动清空前一行内容
# count = 0
# for line in f:
#     if count == 4:
#         print('-----------我是分割线------------')
#         count += 1
#         continue
#     else:
#         print(line.strip())
#         count = count+1

# print(f.tell())
# print(f.readline())
# print(f.readline())
# print(f.tell())
# f.seek(100)
# print(f.readline())

# print(f.encoding)   # 打印编码方式
# print(f.fileno())   # 打印文件编号
# print(f.seekable()) # 判断文件光标是否可移动/f.readable 判断文件是否可读/ f.writeable 判断文件是否可写
#
# f.close()
#
# p = open('yesterday', 'w', encoding='utf-8')
# p.write('hello1')
# p.flush()   # 刷新缓冲区

# f.seek(10)
# f.truncate(20)  # 移动光标对截断没用，都是从开头进行

# f = open('yesterday', 'r+', encoding='utf-8')   # 文件句柄 读写
# f = open('yesterday', 'w+', encoding='utf-8')   # 文件句柄 写读
# f = open('yesterday', 'a+', encoding='utf-8')   # 文件句柄 追加读写
# f = open('yesterday', 'rb')   # 文件句柄 二进制文件 不能进行编码
f = open('yesterday', 'wb')   # 文件句柄 二进制文件 不能进行编码

# print(f.readline())
# print(f.readline())
# print(f.readline())
# f.tell()
# f.write('----------jim--------')
# print(f.readline())

# f.write('----------jim--------')
# f.write('----------jim--------')
# f.write('----------jim--------')
# f.write('----------jim--------')
# f.seek(10)
# print(f.readline())

# print(f.readline())
# print(f.readline())
# print(f.readline())

f.write("hello binary\n".encode())  # 文件以二进制编码
f.close()

下面的·是进度条代码：

# !/usr/bin/env python
# -*-coding:UTF-8-*-

import sys,time
for i in range(50):
    sys.stdout.write('#')
    sys.stdout.flush()
    time.sleep(0.1)