Python学习笔记025

文件读写模式

# r+ 表示读和写，光标在起始位置，读操作默认从0开始，写操作默认从末尾开始
f=open('poem8','r+',encoding='utf8')
print(f.tell())
print(f.readline())
# f.seek(0)

# .write默认添加在末尾
f.write('\nHuawei')

f.close()

# w+ 表示写和读，默认清空文件内容
f=open('poem8','w+',encoding='utf8')
print(f.readline())
# f.seek(0)

# .write默认添加在末尾
f.write('Huawei')

# 光标默认在末尾，后面内容为空
print(f.readline())

f.close()

# a+ 表示追加，光标默认在末尾
f=open('poem8','a+',encoding='utf8')
print(f.tell())
print(f.readline())
# f.seek(0)

# .write默认添加在末尾
f.write('\nHuawei')

f.close()

同时管理多个文件

# with打开的文件，自动关闭
# f=open('poem8','r+',encoding='utf8')
with open('poem8','r') as f:
    f.readline()
    f.read()

print()

# with同时管理多个文件
# f_read=open('poem8','r',encoding='utf8')
# f_write=open('poem9','w',encoding='utf8')
with open('poem8','r') as f_read, open('poem9','w') as f_write:
    for line in f_read:
        f_write.write(line)