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>>> f = open("130.txt")
>>> dir(f)  #查看方法
['_CHUNK_SIZE', '__class__', '__del__', '__delattr__', '__dict__', '__dir__', '__doc__', '__enter__', '__eq__', '__exit__', '__format__', '__ge__', '__getattribute__', '__getstate__', '__gt__', '__hash__', '__init__', '__init_subclass__', '__iter__', '__le__', '__lt__', '__ne__', '__new__', '__next__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__sizeof__', '__str__', '__subclasshook__', '_checkClosed', '_checkReadable', '_checkSeekable', '_checkWritable', '_finalizing', 'buffer', 'close', 'closed', 'detach', 'encoding', 'errors', 'fileno', 'flush', 'isatty', 'line_buffering', 'mode', 'name', 'newlines', 'read', 'readable', 'readline', 'readlines', 'seek', 'seekable', 'tell', 'truncate', 'writable', 'write', 'writelines']

f = open("./codes/130.txt")  #当在上级目录时指定文件
for line in f:print(line)

>>> nf = open("txtfile.txt","w")  #创建txtfile.txt文件
>>> nf.write("This is a new file")  #文件中添加一句话，并返回字符串长度
18
>>> nf.close()   #关闭打开的文件

>>> f = open("txtfile.txt")
>>> f
<_io.TextIOWrapper name='txtfile.txt' mode='r' encoding='UTF-8'>
>>> f = open("txtfile.txt","r")
>>> f
<_io.TextIOWrapper name='txtfile.txt' mode='r' encoding='UTF-8'>

>>> fn = open("mdfile.md","a")
>>> fn
<_io.TextIOWrapper name='mdfile.md' mode='a' encoding='UTF-8'>
>>> fn.write("python can helo you to be agreat programmer.")
44
>>> fn.close()

>>> with open("mdfile.md","a") as f:
...     f.write("\nI am a Pythoner.")
...
17

>>> import os
>>> file_stat = os.stat("mdfile.md")  #使用os模块读取文件属性
>>> file_stat
os.stat_result(st_mode=33188, st_ino=8672850, st_dev=16777220, st_nlink=1, st_uid=501, st_gid=20, st_size=61, st_atime=1505309783, st_mtime=1505309775, st_ctime=1505309775)
>>> file_stat.st_ctime
1505309775.0
>>> import time    #使用time模块读取时间
>>> time.localtime(file_stat.st_ctime)
time.struct_time(tm_year=2017, tm_mon=9, tm_mday=13, tm_hour=21, tm_min=36, tm_sec=15, tm_wday=2, tm_yday=256, tm_isdst=0)

>>> f = open("mdfile.md")
>>> f.read(12)  #读取前12个字符
'python can h'
>>> f.read()    #如果不指定就输出到EOF为止(End of file)
'elo you to be agreat programmer.\nI am a Pythoner.'   #指针的原因没有读取前部分

>>> f.readline()   #每执行一次读取一行
'python can helo you to be agreat programmer.\n'
>>> f.readline()
'I am a Pythoner.'
>>> f.readline()
''

>>> f = open("mdfile.md")
>>> f.readlines()
['python can helo you to be agreat programmer.\n', 'I am a Pythoner.']
>>> f = open("mdfile.md")
>>> for line in f.readlines(): print(line)
...
python can helo you to be agreat programmer.I am a Pythoner.
>>> f = open("mdfile.md")
>>> for line in f: print(line)   #看似相同其实不同，readlines已经在内存中生成列表
...
python can helo you to be agreat programmer.I am a Pythoner.

>>> import fileinput
>>> for line in fileinput.input("you.md"): print(line,end='')
...
You Raise Me Up
When I am down 当我失意低落之时
and, oh my soul, so weary; 我的精神，是那么疲倦不堪
When troubles come 当烦恼困难袭来之际
and my heart burdened be; 我的内心，是那么负担沉重
Then, I am still 然而，我默默的伫立
and wait here in the silence, 静静的等待
Until you come 直到你的来临
and sit awhile with me. 片刻地和我在一起

>>> f = open("you.md")
>>> f.readline()
'You Raise Me Up\n'
>>> f.readline()
'When I am down 当我失意低落之时\n'
>>> f.tell()            #查看指针位置
56
>>> f.seek(0)        #重置指针位置
0
>>> f.readline()
'You Raise Me Up\n'
>>> f.tell()
16
>>> f.readline()
'When I am down 当我失意低落之时\n'
>>> f.seek(4)       #将指针移动到对应位置
4
>>> f.tell()
4
>>> f.readline()
'Raise Me Up\n'