Python文件操作

#读模式
f = open("abc.txt","r",encoding="utf-8")
dat = f.read()
print(dat)
f.close()
#写模式（覆盖）
f_write = open("abc.txt","w",encoding="utf-8")
f_write.write("111 222 333 5555")
f.close()
#追加模式
f_add = open("abc.txt","a",encoding="utf-8")
f_add.write("\n888\n")
f.close()

#句柄
with open("abc.txt","r",encoding="utf-8") as f_read1,\
        open("abc.txt","a",encoding="utf-8") as f_add1:
    print(f_read1.read())
    print(f_add1.write("989800000\n"))

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#从哪个字节开始读

f_read1.seek()

#截取，截取多少个字节，其实就是写

f_write.truncate()

#read很特殊，5不一定代表5个字节

f_read1.read(5)

#光标所在的位置

f_read1.tell()

#写入硬盘

f_read1.flush()

#查看open文件的编码

f_read1.encoding

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#文件读取最后一行,想到seek()
f1 = open("abc.txt","rb")
def file_read_last():
    offs = -10
    while True:
        f1.seek(offs,2)
        d = f1.readlines()
        print("seek范围：%s" %offs)
        print("文件的其它行内容：%s" % (d[-1]))
        if len(d) > 1:
            print("文件的最后一行内容：%s" %(d[-1].decode('utf-8')))
            break
        offs*=2

file_read_last()