Python Tutorial ( PDFDrive )

Recommendations

Info

Using Cookies in CGI HTTP protocol is a stateless protocol. But for a commercial website, it is required to maintain session informationamong different pages. For example, one user registration ends after completing many pages. But how tomaintain user's session information across all the web pages.In many situations, using cookies is the most efficient method of remembering and tracking preferences,purchases, commissions, and other information required for better visitor experience or site statistics.How It Works? Your server sends some data to the visitor's browser in the form of a cookie. The browser mayaccept the cookie. If it does, it is stored as a plain text record on the visitor's hard drive. Now,when the visitor arrives at another page on your site, the cookie is available for retrieval. Onceretrieved, your server knows/remembers what was stored.Cookies are a plain text data record of 5 variable-length fields:• Expires : The date the cookie will expire. If this is blank, the cookie will expire when the visitor quits thebrowser.• Domain : The domain name of your site.• Path : The path to the directory or web page that sets the cookie. This may be blank if you want to retrievethe cookie from any directory or page.• Secure : If this field contains the word "secure", then the cookie may only be retrieved with a secure server. Ifthis field is blank, no such restriction exists.• Name=Value : Cookies are set and retrieved in the form of key and value pairs.Setting up Cookies It is very easy to send cookies to browser. These cookies will be sent along with HTTP Header before to Contenttypefield. Assuming you want to set UserID and Password as cookies. So cookies setting will be done as follows:#!/usr/bin/pythonprint "Set-Cookie:UserID=XYZ;\r\n"print "Set-Cookie:Password=XYZ123;\r\n"print "Set-Cookie:Expires=Tuesday, 31-Dec-2007 23:12:40 GMT";\r\n"print "Set-Cookie:Domain=www.tutorialspoint.com;\r\n"print "Set-Cookie:Path=/perl;\n"print "Content-type:text/html\r\n\r\n"...........Rest of the HTML Content....From this example, you must have understood how to set cookies. We use Set-Cookie HTTP header to setcookies.Here, it is optional to set cookies attributes like Expires, Domain and Path. It is notable that cookies are set beforesending magic line "Content-type:text/html\r\n\r\n.Retrieving Cookies It is very easy to retrieve all the set cookies. Cookies are stored in CGI environment variable HTTP_COOKIE andthey will have following form:key1=value1;key2=value2;key3=value3....TUTORIALS POINT Simply Easy Learning
Here is an example of how to retrieve cookies.#!/usr/bin/python# Import modules for CGI handlingfrom os import environimport cgi, cgitbif environ.has_key('HTTP_COOKIE'):for cookie in map(strip, split(environ['HTTP_COOKIE'], ';')):(key, value ) = split(cookie, '=');if key == "UserID":user_id = valueif key == "Password":password = valueprint "User ID = %s" % user_idprint "Password = %s" % passwordThis will produce the following result for the cookies set by above script:User ID = XYZPassword = XYZ123File Upload Example: To upload a file, the HTML form must have the enctype attribute set to multipart/form-data. The input tag withthe file type will create a "Browse" button.<html><body><form enctype="multipart/form-data"action="save_file.py" method="post"><p>File: <input type="file" name="filename" /></p><p><input type="submit" value="Upload" /></p></form></body></html>The result of this code is the following form:File:UploadAbove example has been disabled intentionally to save people uploading file on our server, but you can try abovecode with your server.Here is the script save_file.py to handle file upload:#!/usr/bin/pythonimport cgi, osimport cgitb; cgitb.enable()form = cgi.FieldStorage()TUTORIALS POINT Simply Easy Learning
Page 1 and 2:
Python Tutorial
Page 3 and 4:
ABOUT THE TUTORIALPython TutorialPy
Page 5 and 6:
Example: ..........................
Page 7 and 8:
Return Value ......................
Page 9 and 10:
Description .......................
Page 11 and 12:
Syntax ............................
Page 13 and 14:
Example ...........................
Page 15 and 16:
Parameters ........................
Page 17 and 18:
Return Value ......................
Page 19 and 20:
Parameters ........................
Page 21 and 22:
Parameters ........................
Page 23 and 24:
Locating Modules: .................
Page 25 and 26:
Parameters ........................
Page 27 and 28:
Description .......................
Page 29 and 30:
Return Value ......................
Page 31 and 32:
Example ...........................
Page 33 and 34:
Parameters ........................
Page 35 and 36:
Regular-expression Modifiers - Opti
Page 37 and 38:
Starting a New Thread: ............
Page 39 and 40:
Example: ..........................
Page 41 and 42:
CHAPTER1Python OverviewPython is a
Page 43 and 44:
CHAPTER2Python EnvironmentBefore we
Page 45 and 46:
• To use this installer python-XY
Page 47 and 48:
-c cmd run Python script sent in as
Page 49 and 50:
This will produce the following res
Page 51 and 52:
file_name = raw_input("Enter filena
Page 53 and 54:
$ python -husage: python [option] .
Page 55 and 56:
print 'Input file is "', inputfilep
Page 57 and 58:
Here, an integer object is created
Page 59 and 60:
Python Lists: Lists are the most v
Page 61 and 62:
FunctionDescriptionint(x [,base])Co
Page 63 and 64:
CHAPTER5Python Basic OperatorsWhat
Page 65 and 66:
Line 4 - Value of c is 2Line 5 - Va
Page 67 and 68:
Line 5 - a is greater than bLine 6
Page 69 and 70:
| Binary OR Operator copies a bit i
Page 71 and 72:
else:print "Line 3 - a and b are tr
Page 73 and 74:
if ( id(a) == id(b) ):print "Line 2
Page 75 and 76:
When you execute the above program,
Page 77 and 78:
if statementsif...else statementsne
Page 79 and 80:
Example: #!/usr/bin/pythonvar1 = 10
Page 81 and 82:
else:print "Could not find true exp
Page 83 and 84:
Loop Typewhile loopfor loopDescript
Page 85 and 86:
num = raw_input("Enter a number :")
Page 87 and 88:
Good bye!Iterating by Sequence I
Page 89 and 90:
11 is prime13 is prime17 is prime19
Page 91 and 92:
continue statement The continue st
Page 93 and 94:
CHAPTER8Python NumbersNumber data t
Page 95 and 96:
max(x1, x2,...)min(x1, x2,...)modf(
Page 97 and 98:
Syntax Following is the syntax for
Page 99 and 100:
import math# This will import math
Page 101 and 102:
import mathmath.log10( x )Note: Thi
Page 103 and 104:
modf(x) Description The method modf
Page 105 and 106:
round( x [, n] )Parameters • x --
Page 107 and 108:
Return Value This method returns a
Page 109 and 110:
seed([x]) Description The method se
Page 111 and 112:
Page 113 and 114:
asin(x)Note: This function is not a
Page 115 and 116:
print "atan2(-10,10) : ", math.atan
Page 117 and 118:
Note: This function is not accessib
Page 119 and 120:
import mathprint "degrees(3) : ", m
Page 121 and 122:
CHAPTER9Python StringsStrings are a
Page 123 and 124:
+ Concatenation - Adds values on ei
Page 125 and 126:
TAB ( \t ) and they will show up th
Page 127 and 128:
14151617181920212223242526272829303
Page 129 and 130:
str = "this is string example....wo
Page 131 and 132:
Return Value This method returns a
Page 133 and 134:
Description The method expandtabs()
Page 135 and 136:
Traceback (most recent call last):F
Page 137 and 138:
Let us compile and run the above pr
Page 139 and 140:
str = "This is string example....wo
Page 141 and 142:
str = "-";seq = ("a", "b", "c"); #
Page 143 and 144:
lstrip() Description The method lst
Page 145 and 146:
Max character: xmin(str) Descriptio
Page 147 and 148:
str = "this is really a string exam
Page 149 and 150:
Parameters • chars -- You can sup
Page 151 and 152:
Parameters• str -- This is the st
Page 153 and 154:
Parameters • NAReturn Value This
Page 155 and 156:
Example The following example shows
Page 157 and 158:
CHAPTER10Python ListsThe most basic
Page 159 and 160:
Python Expression Results Descripti
Page 161 and 162:
Page 163 and 164:
list( seq )Parameters • seq -- Th
Page 165 and 166:
Return Value If elements are of th
Page 167 and 168:
list.insert(index, obj)Parameters
Page 169 and 170:
Page 171 and 172:
CHAPTER11Python TuplesAtuple is a s
Page 173 and 174:
len((1, 2, 3)) 3 Length(1, 2, 3) +
Page 175 and 176:
-11-1len(tuple) Description The met
Page 177 and 178:
min value element : 200tuple(seq) D
Page 179 and 180:
#!/usr/bin/pythondict = {'Name': 'Z
Page 181 and 182:
34str(dict)Produces a printable str
Page 183 and 184:
type(variable) Description The meth
Page 185 and 186:
Page 187 and 188:
Page 189 and 190:
Return Value This method does not
Page 191 and 192:
CHAPTER13Python Date & TimeApython
Page 193 and 194:
#!/usr/bin/pythonimport time;localt
Page 195 and 196:
import timeprint "time.altzone %d "
Page 197 and 198:
Parameters • sec -- These are the
Page 199 and 200:
Page 201 and 202:
• %w - day of the week as a decim
Page 203 and 204:
time.time( ) Description The metho
Page 205 and 206:
2time.tznameAttribute time.tzname i
Page 207 and 208:
CHAPTER14Python FunctionAfunction i
Page 209 and 210:
#!/usr/bin/python# Function definit
Page 211 and 212:
return;# Now you can call printinfo
Page 213 and 214:
Inside the function : 30Outside the
Page 215 and 216:
A module is loaded only once, regar
Page 217 and 218:
'sqrt', 'tan', 'tanh']Here, the spe
Page 219 and 220:
CHAPTER16Python Files I/OThis chapt
Page 221 and 222:
rb+WWbw+wb+AAba+ab+Opens a file for
Page 223 and 224:
fo.write( "Python is a great langua
Page 225 and 226:
EXAMPLE: Following is the example t
Page 227 and 228:
operations from the operating syste
Page 229 and 230:
# Close opened filefo.close()Let us
Page 231 and 232:
Parameters • NAReturn Value This
Page 233 and 234:
Page 235 and 236:
Parameters • offset -- This is th
Page 237 and 238:
Parameters • size -- If this opti
Page 239 and 240:
Description The method writelines()
Page 241 and 242:
14151617181920212223242526272829303
Page 243 and 244:
53545556575859606162os.symlink(src,
Page 245 and 246:
Page 247 and 248:
• stat.S_IRGRP: Read by group.•
Page 249 and 250:
os.chroot("/tmp/usr")print "Changed
Page 251 and 252:
Parameters • fd -- This is the or
Page 253 and 254:
import os, sys# First go to the "/v
Page 255 and 256:
Description The method fchown() cha
Page 257 and 258:
Description The method fdopen() ret
Page 259 and 260:
{'PC_MAX_INPUT': 2, 'PC_VDISABLE':
Page 261 and 262:
Page 263 and 264:
# Open a filefd = os.open( "foo.txt
Page 265 and 266:
print "Current working dir : %s" %
Page 267 and 268:
path = "/var/www/html/foo.txt"fd =
Page 269 and 270:
Page 271 and 272:
_vti_txtrobots.txtitemlistingresume
Page 273 and 274:
# Close opened fileos.close( fd )#
Page 275 and 276:
dev_num = os.makedev(major_dnum, mi
Page 277 and 278:
Page 279 and 280:
-rw-------. 1 root root 0 Apr 30 02
Page 281 and 282:
os.pathconf(path, name) Descriptio
Page 283 and 284:
Description The method popen() open
Page 285 and 286: # !/usr/bin/pythonimport ossrc = '/
Page 287 and 288: Syntax Following is the syntax for
Page 289 and 290: Return Value This method does not
Page 291 and 292: # stat informationstatinfo = os.sta
Page 293 and 294: Description The method tcgetpgrp()
Page 295 and 296: os.tempnam(dir, prefix)Parameters
Page 297 and 298: Description The method ttyname() re
Page 299 and 300: Return Value This method does not
Page 301 and 302: Return Value This method returns t
Page 303 and 304: KeyErrorNameErrorUnboundLocalErrorE
Page 305 and 306: ......................else:If there
Page 307 and 308: print "Error: can\'t find file or r
Page 309 and 310: self.args = argSo once you defined
Page 311 and 312: 'Optional class documentation strin
Page 313 and 314: For the above class let's try to ac
Page 315 and 316: print 'Calling child method'c = Chi
Page 317 and 318: Data Hiding: An object's attribute
Page 319 and 320: groups()This method returns all mat
Page 321 and 322: SYNTAX: re.sub(pattern, repl, strin
Page 323 and 324: \s Matches whitespace. Equivalent t
Page 325 and 326: Backreferences: This matches a prev
Page 327 and 328: CHAPTER20Python CGI ProgrammingWhat
Page 329 and 330: If you click hello.py, then this pr
Page 331 and 332: Simple URL Example : Get Metho
Page 333 and 334: </form>The result of this code is t
Page 335: text_content = form.getvalue('textc
Page 339 and 340: CHAPTER21Python Database AccessThe
Page 341 and 342: EXAMPLE: Following is the example o
Page 343 and 344: ('Mac', 'Mohan', 20, 'M', 2000)try:
Page 345 and 346: DELETE Operation: DELETE operation
Page 347 and 348: ProgrammingErrorSubclass of Databas
Page 349 and 350: The socket Module: To create a so
Page 351 and 352: Protocol Common function Port No Py
Page 353 and 354: Subject: SMTP e-mail testThis is a
Page 355 and 356: try:smtpObj = smtplib.SMTP('localho
Page 357 and 358: count = 0while count < 5:time.sleep
Page 359 and 360: Synchronizing Threads: The threadi
Page 361 and 362: thread = myThread(threadID, tName,
Page 363 and 364: <stars>10</stars><description>Talk
Page 365 and 366: print "Rating:", self.ratingelif se
Page 367 and 368: Format: DVDRating: PGDescription: T
Page 369 and 370: Tkinter Widgets Tkinter provides v
Page 371 and 372: fgfontheighthighlightcolorimagejust
Page 373 and 374: WidthXscrollincrementXscrollcommand
Page 375 and 376: pattern when it is over the checkbu
Page 377 and 378: The Entry widget is used to accept
Page 379 and 380: E1 = Entry(top, bd =5)E1.pack(side
Page 381 and 382: Optionanchorbgbitmapbdcursorfontfgh
Page 383 and 384: selectmodeDetermines how many items
Page 385 and 386: Syntax: Here is the simple syntax t
Page 387 and 388:
Menu The goal of this widget is to
Page 389 and 390:
filemenu.add_command(label="Exit",
Page 391 and 392:
Example: Try the following example
Page 393 and 394:
WidthWraplengthWidth of the label i
Page 395 and 396:
label appears in the top left corne
Page 397 and 398:
Parameters: • master: This repres
Page 399 and 400:
Parameters: • master: This repres
Page 401 and 402:
mark_gravity(mark [,gravity])Return
Page 403 and 404:
Methods & Descriptiondeiconify()Dis
Page 405 and 406:
disabledbackgrounddisabledforegroun
Page 407 and 408:
bgbdThe color of the slider and arr
Page 409 and 410:
fontheightlabelAnchorhighlightbackg
Page 411 and 412:
Standard attributes:Let's take a l
Page 413 and 414:
• family: The font family name as
Page 415 and 416:
B2.pack()B3.pack()B4.pack()B5.pack(
Page 417 and 418:
• "heart"• "heart"• "man"•
Page 419 and 420:
The grid() Method This geometry m
Page 421 and 422:
CHAPTERPython Further Extensions27A
Page 423 and 424:
This table needs to be terminated w
Page 425 and 426:
Passing Function Parameters: Beca
Page 427 and 428:
return (a + b)You can return two va
Page 429 and 430:
CHAPTER28Python Tools/UtilitiesThe
Page 431:
The profile Module: The profile m
show all

Python Tutorial ( PDFDrive )

Create successful ePaper yourself

Delete template?

Save as template?