Python 功能和特点(新手必学)

def function(arg1="",arg2=""): 
  print "arg1: {0}".format(arg1) 
  print "arg2: {0}".format(arg2) 
function("Hello", "World") 
# prints args1: Hello 
# prints args2: World 
function() 
# prints args1: 
# prints args2: 

def foo(*args): # just use "*" to collect all remaining arguments into a tuple 
  numargs = len(args) 
  print "Number of arguments: {0}".format(numargs) 
  for i, x in enumerate(args): 
    print "Argument {0} is: {1}".format(i,x) 
foo() 
# Number of arguments: 0 
foo("hello") 
# Number of arguments: 1 
# Argument 0 is: hello 
foo("hello","World","Again") 
# Number of arguments: 3 
# Argument 0 is: hello 
# Argument 1 is: World 
# Argument 2 is: Again 

import glob 
# get all py files 
files = glob.glob('*.py') 
print files 
# Output 
# ['arg.py', 'g.py', 'shut.py', 'test.py'] 

import itertools as it, glob 
def multiple_file_types(*patterns): 
  return it.chain.from_iterable(glob.glob(pattern) for pattern in patterns) 
for filename in multiple_file_types("*.txt", "*.py"): # add as many filetype arguements 
  print filename 
# output 
#=========# 
# test.txt 
# arg.py 
# g.py 
# shut.py 
# test.py 

 import itertools as it, glob, os 
def multiple_file_types(*patterns): 
  return it.chain.from_iterable(glob.glob(pattern) for pattern in patterns) 
for filename in multiple_file_types("*.txt", "*.py"): # add as many filetype arguements 
  realpath = os.path.realpath(filename) 
  print realpath 
# output 
#=========# 
# C:\xxx\pyfunc\test.txt 
# C:\xxx\pyfunc\arg.py 
# C:\xxx\pyfunc\g.py 
# C:\xxx\pyfunc\shut.py 
# C:\xxx\pyfunc\test.py 

import logging, inspect 
logging.basicConfig(level=logging.INFO, 
  format='%(asctime)s %(levelname)-8s %(filename)s:%(lineno)-4d: %(message)s', 
  datefmt='%m-%d %H:%M', 
  ) 
logging.debug('A debug message') 
logging.info('Some information') 
logging.warning('A shot across the bow') 
def test(): 
  frame,filename,line_number,function_name,lines,index=\ 
    inspect.getouterframes(inspect.currentframe())[1] 
  print(frame,filename,line_number,function_name,lines,index) 
test() 
# Should print the following (with current date/time of course) 
#10-19 19:57 INFO   test.py:9  : Some information 
#10-19 19:57 WARNING test.py:10 : A shot across the bow 
#(, 'C:/xxx/pyfunc/magic.py', 16, '', ['test()\n'], 0)

import uuid 
result = uuid.uuid1() 
print result 
# output => various attempts 
# 9e177ec0-65b6-11e3-b2d0-e4d53dfcf61b 
# be57b880-65b6-11e3-a04d-e4d53dfcf61b 
# c3b2b90f-65b6-11e3-8c86-e4d53dfcf61b 

import hmac,hashlib 
key='1'
data='a'
print hmac.new(key, data, hashlib.sha256).hexdigest() 
m = hashlib.sha1() 
m.update("The quick brown fox jumps over the lazy dog") 
print m.hexdigest() 
# c6e693d0b35805080632bc2469e1154a8d1072a86557778c27a01329630f8917 
# 2fd4e1c67a2d28fced849ee1bb76e7391b93eb12 

import pickle 
variable = ['hello', 42, [1,'two'],'apple'] 
# serialize content 
file = open('serial.txt','w') 
serialized_obj = pickle.dumps(variable) 
file.write(serialized_obj) 
file.close() 
# unserialize to produce original content 
target = open('serial.txt','r') 
myObj = pickle.load(target) 
print serialized_obj 
print myObj 
#output 
# (lp0 
# S'hello' 
# p1 
# aI42 
# a(lp2 
# I1 
# aS'two' 
# p3 
# aaS'apple' 
# p4 
# a. 
# ['hello', 42, [1, 'two'], 'apple'] 

import json 
variable = ['hello', 42, [1,'two'],'apple'] 
print "Original {0} - {1}".format(variable,type(variable)) 
# encoding 
encode = json.dumps(variable) 
print "Encoded {0} - {1}".format(encode,type(encode)) 
#deccoding 
decoded = json.loads(encode) 
print "Decoded {0} - {1}".format(decoded,type(decoded)) 
# output 
# Original ['hello', 42, [1, 'two'], 'apple'] - <type 'list'=""> 
# Encoded ["hello", 42, [1, "two"], "apple"] - <type 'str'=""> 
# Decoded [u'hello', 42, [1, u'two'], u'apple'] - <type 'list'=""> 

import zlib 
string = """  Lorem ipsum dolor sit amet, consectetur 
        adipiscing elit. Nunc ut elit id mi ultricies 
        adipiscing. Nulla facilisi. Praesent pulvinar, 
        sapien vel feugiat vestibulum, nulla dui pretium orci, 
        non ultricies elit lacus quis ante. Lorem ipsum dolor 
        sit amet, consectetur adipiscing elit. Aliquam 
        pretium ullamcorper urna quis iaculis. Etiam ac massa 
        sed turpis tempor luctus. Curabitur sed nibh eu elit 
        mollis congue. Praesent ipsum diam, consectetur vitae 
        ornare a, aliquam a nunc. In id magna pellentesque 
        tellus posuere adipiscing. Sed non mi metus, at lacinia 
        augue. Sed magna nisi, ornare in mollis in, mollis 
        sed nunc. Etiam at justo in leo congue mollis. 
        Nullam in neque eget metus hendrerit scelerisque 
        eu non enim. Ut malesuada lacus eu nulla bibendum 
        id euismod urna sodales. """
print "Original Size: {0}".format(len(string)) 
compressed = zlib.compress(string) 
print "Compressed Size: {0}".format(len(compressed)) 
decompressed = zlib.decompress(compressed) 
print "Decompressed Size: {0}".format(len(decompressed)) 
# output 
# Original Size: 1022 
# Compressed Size: 423 
# Decompressed Size: 1022