文件

# f=open(r'b.txt','w',encoding='utf-8')
# # print(f.writable())
# f.write('111\n')
# f.write('1111\n')
# f.writelines(['111\n','222\n'])
# f.close()

# a 模式 文件不存在则创建，存在则打开文件，光标直接移到末尾开始追加写
# f=open(r'b.txt','a',encoding='utf-8')
# # print(f.writable())
# f.write('345\n')
# f.write('234\n')
# f.write('235\n')
# f.writelines(['qwe\n','wer\n'])
# f.close()

# f=open(r'b.txt','r',encoding='utf-8')
# # print(f.read())
# # print(f.readlines())
# print(f.readline())
# print(f.readline(),end='')
# print(f.readline(),end='')
# print(f.readline(),end='')
# f.close()

# with open(r'b.txt','r',encoding='utf-8')as f:
    # while True:
    #     print(f.readline())
    # print(f.readline())
    # print(f.readline())
    # print(f.readline())
    # print(f.readline())
    # print(f.readline())
    # print(f.readline())

# with open(r'b.txt', 'r', encoding='utf-8')as f:
#     while True:
#         line=f.readline()
#         if len(line) == 0:
#             break
#         print(line)

# with open(r'b.txt', 'r', encoding='utf-8')as f:
#     for line in f:
#         print(line)

# bytes模式
# with open('timg.jfif','r', encoding='utf-8')as f:
    # pass
    # f.read()

# with open('timg.jfif', 'rb')as f:      #  rb 不能指定字符编码
#     f.read()
#     print(f) # <_io.BufferedReader name='timg.jfif'>

# with open(r'b.txt', 'rb', encoding='utf-8')as f:
#     line=f.read()
#     print(line)  # 报错 ValueError: binary mode doesn't take an encoding argument

# with open(r'b.txt', 'rb')as f:
#     line=f.read()
#     # print(line)  # b'111\r\nqwe\r\nwer\r\n'
#     print(line.decode('utf-8')) # 111 qwe wer

# with open(r'b.txt', 'rb')as f:
#     line=f.read()
#     # print(line)  # b'111\r\nqwe\r\nwer\r\n\xe8\x8b\xb9\xe6\x9e\x9c\r\n'
#     print(line.decode('utf-8')) # 111 qwe wer 苹果

# with open(r'b.txt', 'wb')as f:
#     f.write('RNG,Who is the winner!'.encode('utf-8'))

# with open(r'b.txt', 'ab')as f:
#     f.write('OBOS,Who is the winner!'.encode('utf-8'))

# cp
# 源大小的问题
# 文件打开模式的问题

# with open('rfile','rb')as read_f,\
#     open('wfile','wb')as write_f:
#     for line in read_f:
#         write_f.write(line)
#         write_f.flush() # 写一行刷一行 （了解）

# import sys # 导入模块，把别人写好的模块拿过来用
# print(sys.argv) # 专门接受你执行脚本时给他传的参数
# 脚本文件就是一个文件代表一个程序

# 文件修改

# with open(r'b.txt', 'r', encoding='utf-8')as f:
#     data=f.read()
#     # print(data)
#     # print(data.replace('Who','Rambo')) # 字符串不可以更改
#     data=data.replace('Who','Rambo') # 在内存里更改
#     print(data)

# import os 文件过大就撑死了
# with open(r'b.txt', 'r', encoding='utf-8')as f1,\
#     open(r'.b.txt.swap','w',encoding='utf-8')as f2:
#     data = f1.read()
#     data = data.replace('Who', 'Rambo')
#     f1.write(data)
# os.remove('b.txt')
# os.rename('.b.txt.swap','b,txt')

# with open(r'b.txt', 'r', encoding='utf-8')as read_f,\
# #     open(r'.b.txt.swap','w',encoding='utf-8')as wf:
# #     fou line in read_f:
# #     if 'Who' in line:
# #         line=line.replace('Who', 'Rambo')
# #         wf.write(line)
# # os.remove('b.txt')
# # os.rename('.b.txt.swap','b,txt')