PythonGuide/InputOutput

.close()

.read(num=None)

.readline()

.readlines()

.tell()

.fseek(offset, whence=0)

.write(s)

.writelines(seq_of_strings)

.fileno()

.flush()

.name

.mode

.encoding

.closed

FNAME="iotest.xcd"
txt="""
line 1
line 2
line 3
line 4
line 5
line 6
line 7
some text
yada yada yada!
"""
f=open(FNAME, "w")
print f.fileno()
print f.name
print f.mode
print f.closed
f.write(txt)
f.close()
print f.closed

3
iotest.xcd
w
False
True

f=open(FNAME, "r")
lines=f.readlines()
for line in lines:
    print "LINE = > ", line, #avoid printing a new line.
الناتج
LINE = >  
LINE = >  line 1
LINE = >  line 2
LINE = >  line 3
LINE = >  line 4
LINE = >  line 5
LINE = >  line 6
LINE = >  line 7
LINE = >  some text
LINE = >  yada yada yada!

striky@striky-desktop:~$ python myecho.py hello world 123 "78 yay" 
Number of arguments:  5 
myecho.py 
hello 
world 
123 
78 yay

myecho.py
#!bin/python 
 
from sys import argv # arguments vector. 
 
print "Number of arguments: ", len(argv) 
 
for arg in argv: 
        print arg

import os
import os.path as op

os.uname()

print os.uname()
 
#('Linux', 'striky-desktop', '2.6.24-21-generic', '#1 SMP Tue Oct 21 23:43:45 UTC 2008', 'i686')

os.getcwd()

print os.getcwd()
 
/home/striky/workspace/pytut/src

os.getcwdu()

os.environ

for key, val in os.environ.items():
    print key, " => ", val

os.getenv(key, default)

print os.getenv("HOME")

def isroot():
 
	return os.getenv("USER")=="root"

os.putenv(key, value)

os.unsetenv(key)

os.chdir(to)

print os.getcwd()
 
os.chdir("/home/striky")
print os.getcwd()
os.chdir("Music")
print os.getcwd()
 
output
/home/striky/workspace/pytut/src
/home/striky
/media/s3/Music

os.listdir(path)

p=os.getcwd() #/home/striky/workspace/pytut/src
print os.listdir(p)
['userstringtest.py', 'iosess.py', 'gcombo.py', 'iohelpers.py', 'oopsample.py', 'iotest.xcd', 'gtk1.py', 'complpath.py']

os.link(src,dest)

os.symlink(src, dest)

os.unlink(path)

os.remove(path)

os.rmdir(path)

os.rename(src, dest)

os.removedirs(path)

os.removedirs('foo/bar/baz')

chmod(path, mode)

chown(path, uid, gid)

print os.sep # /

/home/striky

print os.curdir #.

print os.altsep#None

print os.pardir#..

print os.extsep#.

print os.pathsep#:

print repr(os.linesep)#\n

p=os.getcwd() #/home/striky/workspace/pytut/src
F=p+r'/'+"iohelpers.py"
print op.basename(F)
 
print op.isfile(F)
print op.islink(F)
print op.isabs(F)
print op.isdir(F)
print op.isdir(p)
print op.ismount("/media/s3")
print op.abspath(F)
print op.dirname(F)
print op.split(F)
print op.splitdrive(F)
print op.splitext(F)
print op.exists(F+"xx")#Nope!
print op.getatime(F) #last access time
print op.getmtime(F) #last modification time
print op.getsize(F)  #file size.
 
print op.join("/home", "striky", "Music")

iohelpers.py
True
False
True
False
True
True
/home/striky/workspace/pytut/src/iohelpers.py
/home/striky/workspace/pytut/src
('/home/striky/workspace/pytut/src', 'iohelpers.py')
('', '/home/striky/workspace/pytut/src/iohelpers.py')
False
1226557143.0
1226557142.0
521
/home/striky/Music
('/home/striky/workspace/pytut/src/iohelpers', '.py')

exists(path)

isfile(path)

isdir(path)

islink(path)

ismount(path)

isabs(path)

basename(path)

abspath(path)

dirname(path)

getatime(path)

getmtime(path)

getctime(path)

getsize(path)

join(a)

split(path)

splitdrive(path)

splitext(path)

>>>F = open(fileName, 'w')
>>>print >> F, 'Hola'  #It will write the Hola word to the file that we opened
>>>F.close()
 
>>>F=open(fileName, 'r')
>>>for line in F.readlines(): print line

Hola  #Output!

>>> f = open('C:\\2.txt', 'w') #Open 2.txt for writing mode.
>>> print >> f, 'Hola!'  #Add 'Hola' to it
>>> print >> f, 'Hello!' # same
>>> print >> f, 'Using File Pointer !' #the same
>>> f.close() #closing the file handler.
>>> f = open('C:\\2.txt', 'r')  # Open in reading mode.
>>> for line in f.readlines(): #iterates through the file lines
	print line #printing each line.

#Here is the output.	        
Hola!
 
Hello!
 
Using File Pointer !

>>>f.close() #closing the handler.

>>> f=open('C:\\2.txt', 'a')
>>> print >> f, 'Programming Fr34ks r0x!'
>>> print >> f, 'File pointers are',  #Note : this comma is used to avoid printing a new line.
>>> print >> f, ' so great' # added to the line 'File pointers are'
>>> f.close()

>>> f=open('C:\\2.txt', 'r')
>>> for line in f.readlines():
	print line

# The output 
 
Hola!
Hello!
Using File Pointer !
Programming Fr34ks r0x!
File pointer are  so great

[program]
name = SVM
version = 0.2.4
license = GPLv3
 
[author]
name = Ahmed Youssef
email = guru.python@gmail.com

from ConfigParser import *

cp=SafeConfigParser() #create an object of SafeConfigParser

cp.read("tst.cfg") #read by filename.

.add_section(section)

.set(section, key, value)

.sections()

.has_section(section)

.get(section, key)

.options(section)

.has_option(section, option)

.items(section)

[('name', 'Ahmed Youssef'), ('email', 'guru.python@gmail.com')]

.write(fp)

    SECTCRE = re.compile(
 
        r'\['                                 # [
 
        r'(?P<header>[^]]+)'                  # very permissive!
 
        r'\]'                                 # ]
 
        )

    OPTCRE = re.compile(
 
        r'(?P<option>[^:=\s][^:=]*)'          # very permissive!
 
        r'\s*(?P<vi>[:=])\s*'                 # any number of space/tab,
 
                                              # followed by separator
 
                                              # (either : or =), followed
 
                                              # by any # space/tab
 
        r'(?P<value>.*)$'                     # everything up to eol
 
        )

from ConfigParser import *
import sys
 
cp=SafeConfigParser() #create an object of SafeConfigParser
 
cp.read("tst.cfg") #read by filename.
 
print cp
print "Sections: ", cp.sections()
print "Options under [program]: ", cp.options("program")
print cp.items("author")
cp.add_section("links")
cp.set("links", "pf", "http://www.programming-fr34ks.net")
cp.set("links", "python", "http://www.python.org")
cp.set("author", "website", "http://ahmedyoussef.wordpress.com")
 
#print it out...
for sec in cp.sections():
    print "--%s:"%sec
    for key, value in cp.items(sec):
        print "\t", key, " = ", value
 
print "--------"
 
cp.write(sys.stdout)

<ConfigParser.SafeConfigParser instance at 0xb7dc0f8c>
Sections:  ['program', 'author']
Options under [program]:  ['version', 'name', 'license']
[('name', 'Ahmed Youssef'), ('email', 'guru.python@gmail.com')]
--program:
	version  =  0.2.4
	name  =  SVM
	license  =  GPLv3
--links:
	python  =  http://www.python.org
	pf  =  http://www.programming-fr34ks.net
--author:
	website  =  http://ahmedyoussef.wordpress.com
	name  =  Ahmed Youssef
	email  =  guru.python@gmail.com
--------
[program]
version = 0.2.4
name = SVM
license = GPLv3
 
[links]
python = http://www.python.org
pf = http://www.programming-fr34ks.net
 
[author]
website = http://ahmedyoussef.wordpress.com
name = Ahmed Youssef
email = guru.python@gmail.com

ahmed, 19, m 
ayman, 20, m

name, age, sex
ahmed, 19, m 
ayman, 20, m

ahmed, m, 19
wael, m, 20
radwa, f, 19
gina, f, 21
ayman, m, 20

import csv

reader=csv.reader(open("somefile.csv", "rb")) #default dialect. #b as a catch for win32

for row in reader:
    print row, " at: ", reader.line_num

import csv
 
f=open("somefile.csv", "rb")
try:
    reader=csv.reader(f) #default dialect. #b as a catch for win32.
 
    for row in reader:
        print row, " at: ", reader.line_num
 
 
except Exception, ex:
    print ex.message
finally:
    f.close()

    reader=csv.DictReader(f, fieldnames=("name", "age", "sex")) #default dialect. #b as a catch for win32.
 
    for row in reader:
        print row, " at: ", reader.line_num
        print row["name"] #the name column

import csv 
 
f=open("somefile1.csv", "w") 
try: 
 
    writer=csv.writer(f) 
    inputrows=( 
           (1, "ahmed", "ahmedf1@gmail.com"), 
           (2, "ayman", "aymanf2@gmail.com"), 
           (3, "smsm", "smsm@yahoo.com") 
           ) 
 
    headers=("id", "user", "email") 
    writer.writerow(headers) 
 
    for row in inputrows: 
        writer.writerow(row) 
 
except Exception, ex: 
    print ex.message 
 
finally: 
    f.close()