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--- public:it:python [2014/09/22 19:16] – 创建 oakfire
+++ public:it:python [2024/01/15 15:33] (当前版本) – [Tips] oakfire
@@ 行 1: / 行 1: @@
 ====== Python ======
+  * [[https://www.python.org | Officail site: python.org]]
+  * [[http://nbviewer.ipython.org/github/rasbt/python_reference/blob/master/tutorials/key_differences_between_python_2_and_3.ipynb | Key differences between python2 and 3]]
+===== Tips =====
   * 快速开一个静态http服务: 进入文件夹, 然后 ''python -m SimpleHTTPServer 80''
+  * In Terminal, type ''pydoc raw_input'' Read what it says about "raw_input". If you're on Windows try ''python -m pydoc raw_input'' instead. Get out of pydoc by typing ''q'' to quit.
+  * python为动态语言,与js类似, list,dict等object的''=''赋值在默认为引用. 如果不需要引用, 那么拷贝list用''list2 = list1[:]'',之后list2的改动便与list1无关.
+  * python 变快的 9 个技巧：[[https://medium.com/techtofreedom/9-subtle-tricks-to-make-your-python-code-much-faster-50be6dd69a30|9-subtle-tricks-to-make-your-python-code-much-faster]]
+    * 拼接字符串的速度, 直接 ''+'' 快于  ''join()'' 快于 ''+='' 一项项加.
+    * Faster List Creation: Use “[]” Over “list()” 用 ''[]''来初始化列表
+    * Faster Membership Testing: Use a Set Over a List
+    * Faster Data Generation: Use Comprehensions Over For Loops  用内包代替循环
+    * Faster Loops: Prioritize Local Variables 优先使用局部变量
+    * Faster Execution: Prioritize Built-In Modules and Libraries 优先用内置模块和库
+    * Faster Function Calls: Leverage Cache Decorator for Easy Memoization
+    * Faster Infinite Loop: Prefer “while 1” Over “while True” 但是现代解释器基本都优化过， ''while TRUE'' 还更有可读性
+    * Faster Start-Up: Import Python Modules Smartly
+===== 从零开始 =====
+  * [[http://learnpythonthehardway.org/book/ | learn python the hard way]] python2.
+  * Learning more:
+      * [[http://learnrubythehardway.org/|Learn Ruby The Hard Way]] You will learn even more about programming as you learn more programming languages, so try learning Ruby too.
+      * [[https://docs.djangoproject.com/en/1.4/intro/tutorial01/|The Django Tutorial]] and try to build a web application with the [[https://www.djangoproject.com/|Django Web Framewor]].
+      * [[http://www.scipy.org/|SciPy]] if you're into science, math, and engineering and also [[http://dexy.it|Dexy]] for when you want to write awesome papers that incorporate SciPy or any code really.
+      * [[http://www.pygame.org/news.html|PyGame]] and see if you can make a game with graphics and sound.
+      * [[http://pandas.pydata.org/|Pandas]] for doing data manipulation and analysis.
+      * [[http://nltk.org/|Natural Language Tool Kit]] for analyzing written text and writing things like spam filters and chat bots.
+      * [[http://docs.python-requests.org/en/latest/index.html|Requests]] to learn the client side of HTTP and the web.
+      * [[http://simplecv.org/|SimpleCV]] to play with making your computer see things in the real world.
+      * [[http://scrapy.org/|ScraPy]] and try scraping some web sites to get information off them.
+      * [[https://www.panda3d.org/|Panda3D]] for doing 3D graphic and games.
+      * [[http://kivy.org/|Kivy]] for doing user interfaces on desktops and mobile platforms.
+      * [[http://scikit-learn.org/stable/|SciKit-Learn]] for machine learning applications.
+      * [[http://renpy.org/|Ren'Py]] for doing interactive fiction games, similar to what you've built in this book but with pictures.
+  * Notes:<code python>
+# -------------------------------------------------------------------------
+# ex1: Print
+# -*- coding: utf-8 -*-
+print "I'd much rather you 'not'."
+print 'I "said" do not touch this.'
+print "世界,你好"
+# on terminal, run ex1.py
+python ex1.py
+# -------------------------------------------------------------------------
+# ex2: Common
+# This is a common
+print "common" #This is a common too.
+# -------------------------------------------------------------------------
+# ex3: Numbers and Math
+# + - / * % < > <= >=
+# more: **
+print "Result is ", 2*2-3/1, "+", 7%6,"=", 2, "is", 2>1, 2**8
+# -------------------------------------------------------------------------
+# ex4: Variables And Names
+cars = 100
+space_in_a_car = 4.0
+# -------------------------------------------------------------------------
+# ex5: More Variables and Printing
+my_name = 'lucy'
+my_age = 16
+print "My name is %s." % my_name
+print "My name is %s, i am %d old." % ( my_name, my_age )
+# -------------------------------------------------------------------------
+# ex6: Strings and Text
+print "My name is: %r" % "lucy"  # Print "My name is:'lucy'".
+print "My name is: '%s'" % "lucy"  # Print the same.
+my_name = "My name is: %r"
+print my_name % 'lucy' # Print the same.
+# -------------------------------------------------------------------------
+# ex7: More Printing
+print "a" + "b" + "c" * 5 # Print "abccccc"
+# -------------------------------------------------------------------------
+# ex8: Printing, Printing
+formatter = "%r %r %r %r"
+print formatter % (1, 2, 3, 4)
+print formatter % ("one", "two", "three", "four")
+print formatter % (True, False, False, True)
+print formatter % (formatter, formatter, formatter, formatter)
+# -------------------------------------------------------------------------
+# ex9: Printing, Printing, Printing
+# Here's some new strange stuff, remember type it exactly.
+days = "Mon Tue Wed Thu Fri Sat Sun"
+months = "Jan\nFeb\nMar\nApr\nMay\nJun\nJul\nAug"
+print "Here are the days: ", days
+print "Here are the months: ", months
+print """
+There's something going on here.
+With the three double-quotes.
+We'll be able to type as much as we like.
+Even 4 lines if we want, or 5, or 6.
+"""
+# -------------------------------------------------------------------------
+# ex10
+print "\t \\ \" '\"' "
+# -------------------------------------------------------------------------
+# ex11: Asking Questions
+print "How old are you?", # We put a "," (comma) at the end of each print line. This is
+#so print doesn't end the line with a newline character and go to the next line.
+age = raw_input()
+print "So, you're %r old" % age
+# -------------------------------------------------------------------------
+# ex12: Prompting People
+age = raw_input("How old are you ?")
+# -------------------------------------------------------------------------
+# ex13: Parameters, Unpacking, Variables
+from sys import argv
+script, first, second, third = argv
+print "The script is called:", script
+print "Your first variable is:", first
+print "Your second variable is:", second
+print "Your third variable is:", third
+# ex14: Prompting and Passing
+# Nothing impresses me.
+# -------------------------------------------------------------------------
+# ex15: Reading Files
+print "Type the filename :"
+filename= raw_input("> ")
+txt= open(filename)
+print txt_again.read()
+# -------------------------------------------------------------------------
+# ex16: Reading and Writing Files
+# class file's function:
+# close : like save
+# read:
+# seek:
+# readline -- Reads just one line of a text file.
+# truncate -- Empties the file. Watch out if you care about the file.
+# write('stuff')
+# writeline
+my_file.open('tmp.txt', 'w')
+my_file.write('first line \n')
+# ex17: More files
+# Nothing impresses me.
+# -------------------------------------------------------------------------
+# ex18: Names, Variables, Code, Functions
+# create a function by using the word 'def'
+def my_function(*args):
+    arg1,arg2=args
+    print "arg1:%r, arg2:%r" % (arg1, arg2)
+#or
+def print_two_again(arg1, arg2):
+    print "arg1: %r, arg2: %r" % (arg1, arg2)
+# ex19: Functions and Variables
+# ex20: Functions and Files
+# ex21: Functions Can Return Something by "return"
+# ex22: What Do You Know So Far?
+# ex23: Read Some Code
+# ex24: More Practice
+# Nothing impresses me.
+# -------------------------------------------------------------------------
+# ex25: Even More Practice
+# in ex25.py file:
+def break_words(stuff):
+    """This function will break up words for us."""
+    words = stuff.split(' ')
+    return words
+# usage ex25.py in Terminal:
+import ex25
+ex25.break_words("Hello world") # call function 'break_words' in ex25.py
+help(ex25) # show help info about ex25.py
+help(ex25.break_words) # show help info about function break_words in module ex25
+# Typing 'ex25' is annoying. A shortcut is to
+# do your import like this: 'from ex25 import * ' which is like saying, "Import everything from ex25."
+from ex25 import *
+break_words("Hello world")
+# ex26: Congratulations, Take a Test!
+# Nothing.
+# -------------------------------------------------------------------------
+# ex27: Memorizing Logic
+# terms:
+and, or, not, !=, ==, >=, <=, True, False
+# ex28: Boolean Practice
+# Nothing impresses me.
+# -------------------------------------------------------------------------
+# ex29: What If
+# ex30: Else and If
+# ex31: Making Decisions
+people = 20
+cats = 30
+if cars > people:
+    print "We should take the cars."
+elif cars < people:
+    print "We should not take the cars."
+else:
+    print "We can't decide."
+# -------------------------------------------------------------------------
+# ex32: Loops and Lists
+the_count = [1, 2, 3, 4, 5]
+fruits = ['apples', 'oranges', 'pears', 'apricots']
+change = [1, 'pennies', 2, 'dimes', 3, 'quarters']
+# this first kind of for-loop goes through a list
+for number in the_count:
+    print "This is count %d" % number
+for fruit in fruits:
+    print "A fruit of type: %s" % fruit
+# also we can go through mixed lists too
+# notice we have to use %r since we don't know what's in it
+for i in change:
+    print "I got %r" % i
+# we can also build lists, first start with an empty one
+elements = []
+# then use the range function to do 0 to 5 counts
+for i in range(0, 6):
+    print "Adding %d to the list." % i
+    elements.append(i)
+# now we can print them out too
+for i in elements:
+    print "Element was: %d" % i
+# -------------------------------------------------------------------------
+# ex33: While Loops
+i = 0
+numbers = []
+while i < 6:
+    numbers.append(i)
+    i += 1;
+for num in numbers:
+    print num
+# ex34: Accessing Elements of Lists
+# Nothing impresses me.
+# -------------------------------------------------------------------------
+# ex35: Branches and Functions
+from sys import exit
+def gold_room():
+    print "This room is full of gold.  How much do you take?"
+    choice = raw_input("> ")
+    if "0" in choice or "1" in choice:
+        how_much = int(choice)
+    else:
+        dead("Man, learn to type a number.")
+    if how_much < 50:
+        print "Nice, you're not greedy, you win!"
+        exit(0)
+    else:
+        dead("You greedy bastard!")
+def dead(why):
+    print why, "Good job!"
+    exit(0)
+# -------------------------------------------------------------------------
+# ex36: Designing and Debugging
+# ex37: Symbol Review
+# ex38: Doing Things to Lists
+ten_things = "Apples Oranges Crows Telephone Light Sugar"
+print "Wait there are not 10 things in that list. Let's fix that."
+stuff = ten_things.split(' ')
+more_stuff = ["Day", "Night", "Song", "Frisbee", "Corn", "Banana", "Girl", "Boy"]
+while len(stuff) != 10:
+    next_one = more_stuff.pop()
+    print "Adding: ", next_one
+    stuff.append(next_one)
+    print "There are %d items now." % len(stuff)
+print "There we go: ", stuff
+print "Let's do some things with stuff."
+print stuff[1]
+print stuff[-1] # whoa! fancy
+print stuff.pop()
+print ' '.join(stuff) # what? cool!
+print '#'.join(stuff[3:5]) # super stellar!
+# -------------------------------------------------------------------------
+# ex39: Dictionaries, Oh Lovely Dictionaries
+>>> stuff = {'name': 'lucy', 'age': 16}
+>>> print stuff['name']
+lucy
+>>> stuff[1] = "Wow"
+>>> stuff
+{1:'Wow', 'age':16, 'name':'lucy'}
+>>> del stuff['age']
+>>> stuff
+{1:'Wow', 'name':'lucy'}
+#
+for key, value in stuff.items():
+    print "%r : %r" % (key, value)
+# -------------------------------------------------------------------------
+# ex40: Modules, Classes, and Objects
+# Modules Are Like Dictionaries
+# Classes Are Like Modules
+# Objects are Like Import
+# Getting Things from Things
+# I now have three ways to get things from things:
+## dict style
+mystuff['apples']
+## module style
+mystuff.apples()
+print mystuff.tangerine
+## class style
+thing = MyStuff()
+thing.apples()
+print thing.tangerine
+# A First Class Example:
+class Song(object):
+    def __init__(self, lyrics):
+        self.lyrics = lyrics
+    def sing_me_a_song(self):
+        for line in self.lyrics:
+            print line
+happy_bday = Song(["Happy birthday to you",
+                   "I don't want to get sued",
+                   "So I'll stop right there"])
+bulls_on_parade = Song(["They rally around tha family",
+                        "With pockets full of shells"])
+happy_bday.sing_me_a_song()
+bulls_on_parade.sing_me_a_song()
+# ex41: Learning To Speak Object Oriented
+# ex42: Is-A, Has-A, Objects, and Classes
+super
+# -------------------------------------------------------------------------
+# ex43: Basic Object-Oriented Analysis and Design
+# ex44: Inheritance Versus Composition
+class Parent(object):
+    def override(self):
+        print "PARENT override()"
+    def implicit(self):
+        print "PARENT implicit()"
+    def altered(self):
+        print "PARENT altered()"
+class Child(Parent):
+    def override(self):
+        print "CHILD override()"
+    def altered(self):
+        print "CHILD, BEFORE PARENT altered()"
+        super(Child, self).altered()
+        print "CHILD, AFTER PARENT altered()"
+dad = Parent()
+son = Child()
+dad.implicit()
+son.implicit()
+dad.override()
+son.override()
+dad.altered()
+son.altered()
+# multiple inheritance
+class SuperFun(Child, BadStuff):
+    pass
+# Using super() with __init__
+class Child(Parent):
+    def __init__(self, stuff):
+        self.stuff = stuff
+        super(Child, self).__init__()
+# ex45: You Make a Game
+# Nothing impresses me.
+# -------------------------------------------------------------------------
+# ex46: A Project Skeleton
+try:
+    from setuptools import setup
+except ImportError:
+    from distutils.core import setup
+# -------------------------------------------------------------------------
+# ex47: Automated Testing
+nosetests
+from nose.tools import *
+assert_equal
+# Test files go in "tests/" and are named "BLAH_tests.py" otherwise "nosetests" won't run them.
+# -------------------------------------------------------------------------
+# ex48: Advanced User Input
+# A tuple is nothing more than a list that you can't modify.
+# It's created by putting data inside two "("")" with a comma, like a list:
+first_word = ('verb', 'go')
+# Exceptions and Numbers
+def convert_number(s):
+    try:
+        return int(s)
+    except ValueError:
+        return None
+# -------------------------------------------------------------------------
+# ex49: Making Sentences
+# ex50: Your First Website
+# ex51: Getting Input from a Browser
+# ex52: The Start Of Your Web Game
+# Nothing impresses me.
+</code>