Python file Handling--02 file attributes & Standard input/output & command line parameters & file encoding

1 file attributes

File.fileno ()--File descriptor

file.mode--file currently open permissions

file.encoding--file Encoding Format (no output indicates ASCII code)

Whether the file.closed--file is closed

>>> F.fileno ()

3

>>> F.mode

' R+ '

>>> f.encoding

>>> f.closed

False

>>> filter (lambda s:s[:2]!= ' __ ', dir (f))

[' Close ', ' Closed ', ' encoding ', ' errors ', ' Fileno ', ' flush ', ' isatty ', ' mode ', ' name ', ' newlines ', ' next ', ' read ', ' Readin To ', ' readline ', ' readlines ', ' seek ', ' softspace ', ' Tell ', ' truncate ', ' write ', ' writelines ', ' xreadlines ']

2 Standard Documents

Standard input File--sys.stdin

Standard output File--sys.stdout

Standard error File--sys.stderr

You can use these three to redirect the stdout and stderr that the Python program runs to a file

Example-redirect stdout

#stdout. py

Import Sys

print ' Dive in '

Saveout = Sys.stdout

Fsock = open (' Out.log ', ' W ')

sys.stdout = Fsock # Print will be printed to Out.log

print ' This message'll be logged instead of displayed '

Sys.stdout = Saveout

fsock.close () #还原stdout

Reference: http://blog.csdn.net/lanbing510/article/details/8487997

3 File command line arguments

Receive command-line arguments through the argv property of the Sys module. Returns a list,list[0] as the script name, list[1:] all parameters.

argv.py File Contents

# argv.py

Import Sys

print ' Test----'

Argv_list = sys.argv

Print Argv_list

Command line invocation

E:\yc_study\python\ System Learning--mu lesson net \ file processing >python argv.py 1 2 3

Test----

[' argv.py ', ' 1 ', ' 2 ', ' 3 ']

E:\yc_study\python\ System Learning--mu lesson net \ file processing >python argv.py 1 2 age=18

Test----

[' argv.py ', ' 1 ', ' 2 ', ' age=18 ']

4 file Encoding format 4.1Python character encoding detailed

Http://www.cnblogs.com/timdes1/p/7747589.html

4.2 Writing a string in utf-8 format

>>> f=open (' unicode_test.txt ', ' w+ ')

>>> F.read ()

‘‘

>>> f.write (U ' hahaha ')

Traceback (most recent):

File "<stdin>", line 1, in <module>

Unicodeencodeerror: ' ASCII ' codec can ' t encode characters in position 0-2: Ordinal not in range (128)

>>> des_str=unicode.encode (U ' hahaha ', ' utf-8 ')

>>> F.write (DES_STR)

>>> F.seek (0,os. Seek_set)

>>> F.read ()

' \xe5\x93\x88\xe5\x93\x88\xe5\x93\x88 '

4.3 Creating a document in Utf-8 format

Using the Codecs module

>>> f=codecs.open(' Create_utf_8.txt ', ' w ', ' Utf-8 ')

>>> f.encoding

' Utf-8 '

>>> F.close ()

Python file Handling--02 file attributes & Standard input/output & command line parameters & file encoding