python基础之文件操作

文件操作:

#打开文件
'''
f = open("db","r")#只读
f = open("db","w")#只写,先清空原文件
f = open("db","x")#如果文件存在报错,不存在创建并写内容
f = open("db","a")#追加

"+" 表示可以同时读写某个文件
r+, 读写【可读,可写】
w+,写读【可读,可写】
x+ ,写读【可读,可写】
a+, 写读【可读,可写】
r+b,
w+b,
x+b,
a+b, 
最常用的是r+
'''
# f = open("db","r",encoding="utf-8")#以什么编码格式保存
# print(data,type(data))
# f.close()

# f = open("db","rb")# rb 读到的是字节类型,
# data = f.read()
# print(data,type(data))

# f = open("db","ab")
# f.write(bytes("hello",encoding="utf-8"))#追加是以字节类型,写也要以字节类型进行写
# f.close()

# f = open("db","r+",encoding="utf-8")
# date = f.read(1)
# print(f.tell())#告诉当前指针位置,永远是字节
# f.seek(f.tell())#主动调文件指针位置,切位置以后会进行覆盖,永远是以字节的方式
# f.write(777)#当前指针以后向后覆盖
# f.close()

#操作文件
# f.read()#默认无参数,读取全部,如果打开模式有b,则读字节
# f.seek()#指针跳转到某个位置,按照字节
# f.tell()#告诉指针当前位置,按照字节
# f.write()#写,有bytes,写字节。
# f.flush()#强刷
#
# f = open("db","w")
# print(f.readable())#判断是否可读,返回True or False
# f.readline()#只读第一行,再写一遍读取下一行
# f = open("db","r+")
# f.seek(3)
# f.truncate()#截断,指针位置以后的内容清空
# f.close()
#for 循环文件对象
#一行一行的读
# for line in f:
#     print(line)
#  if XX in line: #判断数据是否在读取的内容里面
#read() #无参数,读全部;有参数按字符 # f = open("db","r") # r = f.read() # print(r) # f.close() #文件关闭 # f.close() # with open("db","r") as f: # pass#执行完自动关闭 def close(self, *args, **kwargs): # real signature unknown pass#关闭 def detach(self, *args, **kwargs): # real signature unknown pass def fileno(self, *args, **kwargs): # real signature unknown pass def flush(self, *args, **kwargs): # real signature unknown pass#强制刷新 def isatty(self, *args, **kwargs): # real signature unknown pass def read(self, *args, **kwargs): # real signature unknown pass# def readable(self, *args, **kwargs): # real signature unknown pass#判断是否可读 def readline(self, *args, **kwargs): # real signature unknown pass#仅读一行 def seek(self, *args, **kwargs): # real signature unknown pass#指针跳转某个位置,以字节 def seekable(self, *args, **kwargs): # real signature unknown#判断指针是否可以进行跳转 pass def tell(self, *args, **kwargs): # real signature unknown pass#告诉指针在哪个位置,以字节 def truncate(self, *args, **kwargs): # real signature unknown pass#截断,截断当前指针以后的内容清空 def writable(self, *args, **kwargs): # real signature unknown pass#判断是否可写 def write(self, *args, **kwargs): # real signature unknown pass#

 

posted @ 2017-03-17 11:57  墨羽丶  阅读(116)  评论(0编辑  收藏  举报