Python - using glob to get lists of files and directories

import os.path
# glob is a simple and useful python module. 
# It uses simple regular expressions to match 
# directories and files for a given path.  If 
# you've ever used the command line to 'ls' or 
# 'dir' the currently directory you may be aware 
# that the directory accepts * or ? or [] to 
# match patterns.  glob is a python implementation 
# of this functionality. 
 
import glob
import os
 
# find all the .txt files in the current working directory  
print glob.glob('*.TXT')
# output: 
# ['LICENSE.txt', 'NEWS.txt', 'README.txt'] 
 
# you can also specify a full path 
# Here I'm searching for dll files in python 2.6 
print glob.glob('C:\Python26\DLLs\*.dll')
# output: 
#    ['C:\\Python26\\DLLs\\sqlite3.dll', 
#    'C:\\Python26\\DLLs\\tcl85.dll', 
#    'C:\\Python26\\DLLs\\tclpip85.dll', 
#    'C:\\Python26\\DLLs\\tk85.dll'] 
 
# If you are expecting a great deal of results 
# you should use the glob.iglob method that returns 
# matches as it goes and does not load everything 
# into memory first. 
# glob.iglob() example 
f = glob.iglob('C:\Python26\Lib\*')
 
spitItOut = True
while spitItOut:
    try:
        fileNameAndPath = f.next()
        # since glob gives you the full path you can 
        # use the output with some of the os module's methods 
        if os.path.isfile(fileNameAndPath):
            fileNameAndPath += " is a file." 
        else:
            fileNameAndPath += " is not a file." 
        print fileNameAndPath
    except StopIteration:
        spitItOut = False
 
#output (snipped a bit...since there a lot): 
#    C:\Python26\Lib\abc.py is a file. 
#    ....[snip] 
#    C:\Python26\Lib\compiler is not a file. 
#    ...[another snip] 
#    C:\Python26\Lib\getopt.py is a file. 
#    C:\Python26\Lib\getopt.pyc is a file. 
#    C:\Python26\Lib\getpass.py is a file. 
#    C:\Python26\Lib\gettext.py is a file. 
#    C:\Python26\Lib\glob.py is a file. 
#    C:\Python26\Lib\glob.pyc is a file. 
 
 

Python - printing complex objects with pretty printing

# Pretty printing (using the pprint module) transforms 
# python objects into human readable output. 
# 
# Use pprint when you need to display a complex 
# data structure to users. 
 
 
import string
import pprint
# pprint python doc
 
d = {}
 
for i in string.ascii_lowercase:
    d[i] = string.ascii_lowercase.replace(i, ' ')
 
print "not useful output:" 
print d
# output: 
#   not useful output: 
#   {'a': ' bcdefghijklmnopqrstuvwxyz', 'c': 'ab defghijklmnopqrstuvwxyz', 'b': 
#   'a cdefghijklmnopqrstuvwxyz', 'e': 'abcd fghijklmnopqrstuvwxyz', 'd': 'abc 
#   efghijklmnopqrstuvwxyz', 'g': 'abcdef hijklmnopqrstuvwxyz', 'f': 'abcde ghij 
#   klmnopqrstuvwxyz', 'i': 'abcdefgh jklmnopqrstuvwxyz', 'h': 'abcdefg ijklmnop 
#   qrstuvwxyz', 'k': 'abcdefghij lmnopqrstuvwxyz', 'j': 'abcdefghi klmnopqrstuv 
#   wxyz', 'm': 'abcdefghijkl nopqrstuvwxyz', 'l': 'abcdefghijk mnopqrstuvwxyz', 
#   'o': 'abcdefghijklmn pqrstuvwxyz', 'n': 'abcdefghijklm opqrstuvwxyz', 'q': ' 
#   abcdefghijklmnop rstuvwxyz', 'p': 'abcdefghijklmno qrstuvwxyz', 's': 'abcdef 
#   ghijklmnopqr tuvwxyz', 'r': 'abcdefghijklmnopq stuvwxyz', 'u': 'abcdefghijkl 
#   mnopqrst vwxyz', 't': 'abcdefghijklmnopqrs uvwxyz', 'w': 'abcdefghijklmnopqr 
#   stuv xyz', 'v': 'abcdefghijklmnopqrstu wxyz', 'y': 'abcdefghijklmnopqrstuvwx 
#   z', 'x': 'abcdefghijklmnopqrstuvw yz', 'z': 'abcdefghijklmnopqrstuvwxy '} 
# 
# All the data is there but it is difficult to read. 
# You can use pprint (pretty print) to make things easy to read.  pprint 
#   formats python datastructures to be human readable. 
 
print "human readable output:" 
pprint.pprint(d, indent=4)
# output: 
#human readable output: 
#{   'a': ' bcdefghijklmnopqrstuvwxyz', 
#    'b': 'a cdefghijklmnopqrstuvwxyz', 
#    'c': 'ab defghijklmnopqrstuvwxyz', 
#    'd': 'abc efghijklmnopqrstuvwxyz', 
#    'e': 'abcd fghijklmnopqrstuvwxyz', 
#    'f': 'abcde ghijklmnopqrstuvwxyz', 
#    'g': 'abcdef hijklmnopqrstuvwxyz', 
#    'h': 'abcdefg ijklmnopqrstuvwxyz', 
#    'i': 'abcdefgh jklmnopqrstuvwxyz', 
#    'j': 'abcdefghi klmnopqrstuvwxyz', 
#    'k': 'abcdefghij lmnopqrstuvwxyz', 
#    'l': 'abcdefghijk mnopqrstuvwxyz', 
#    'm': 'abcdefghijkl nopqrstuvwxyz', 
#    'n': 'abcdefghijklm opqrstuvwxyz', 
#    'o': 'abcdefghijklmn pqrstuvwxyz', 
#    'p': 'abcdefghijklmno qrstuvwxyz', 
#    'q': 'abcdefghijklmnop rstuvwxyz', 
#    'r': 'abcdefghijklmnopq stuvwxyz', 
#    's': 'abcdefghijklmnopqr tuvwxyz', 
#    't': 'abcdefghijklmnopqrs uvwxyz', 
#    'u': 'abcdefghijklmnopqrst vwxyz', 
#    'v': 'abcdefghijklmnopqrstu wxyz', 
#    'w': 'abcdefghijklmnopqrstuv xyz', 
#    'x': 'abcdefghijklmnopqrstuvw yz', 
#    'y': 'abcdefghijklmnopqrstuvwx z', 
#    'z': 'abcdefghijklmnopqrstuvwxy '} 
# 
# Formatted in this fashion its easy to see what 
# data is being stored in the dict. 
 
 

Python - hash with md5 and sha1 (and others!)

# There a many reasons to hash data. 
# For this example we'll say that we 
# want to has passwords so we can store 
# them in a database (or file)...or for 
# this example a variable 
 
# hashlib encapsulates the following functionality: 
#   md5 
#   sha1 
#   sha224 
#   sha256 
#   sha384 
#   sha512 
import hashlib
 
# When a user creates their account they'll input 
# a password.  For security purposes you hash 
# the password and store it (so they can log into 
# their account later). 
password = "$uperP@a$$w0rd" 
 
#pass the password to the sha1 constructor 
createSha1 = hashlib.sha1(password)
 
#dump the password out in text 
sha1_password = createSha1.hexdigest()
 
print sha1_password
#output: 
# 2d0b537e6673e1f6baf1c462cd4922dab32ee243 
 
# You'll notice that sha1 creates a 40 character hash. 
# All hashed strings (regardless of original size) will 
# be represented by sha1 as 40 characters. 
print len(sha1_password)
#output: 
# 40 
 
# You can store that hashed password and then later the 
# user will attempt to login.  Take their password and hash 
# it with the same algorithm (sha1 in our example). 
password_attempt_1 = "superP@a$$w0rd" 
password_attempt_2 = "$up3rP@a$$w0rd" 
password_attempt_3 = "$uperP@a$$w0rd" 
 
#take the attempts and hash them so you can compare passwords 
attempt1 = hashlib.sha1(password_attempt_1)
if sha1_password == attempt1.hexdigest():
    print "password attempt 1 is a success" 
else:
    print "password attempt 1 is a failure" 
 
attempt2 = hashlib.sha1(password_attempt_2)
if sha1_password == attempt2.hexdigest():
    print "password attempt 2 is a success" 
else:
    print "password attempt 2 is a failure" 
 
attempt3 = hashlib.sha1(password_attempt_3)
if sha1_password == attempt3.hexdigest():
    print "password attempt 3 is a success" 
else:
    print "password attempt 3 is a failure" 
 
#output: 
#    password attempt 1 is a failure 
#    password attempt 2 is a failure 
#    password attempt 3 is a success 
 
 
# Now that you understand how to use sha1 you 
# understand how to use all of the supported 
# algorithms in hashlib.  They all use the same 
# methods so you can easily adapt your code to 
# any of the hash types. 
# Check out the python docs for hashlib