Python3 入门教程 简单但比较不错

#打开新窗口,输入: 
#! /usr/bin/python 
# -*- coding: utf8 -*- 
s1=input("Input your name:") 
print("你好,%s" % s1) 
''' 

#! /usr/bin/python 
a=2 
b="test" 
c=a+b 

#! /usr/bin/python 
#运行这行程序会出错,提示你字符串和数字不能连接,于是只好用内置函数进行转换 
a=2 
b="test" 
c=str(a)+b 
d="1111" 
e=a+int(d) 
#How to print multiply values 
print ("c is %s,e is %i" % (c,e)) 
''' 

#! /usr/bin/python 
# -*- coding: utf8 -*- 
#列表类似Javascript的数组,方便易用 
#定义元组 
word=['a','b','c','d','e','f','g'] 
#如何通过索引访问元组里的元素 
a=word[2] 
print ("a is: "+a) 
b=word[1:3] 
print ("b is: ") 
print (b) # index 1 and 2 elements of word. 
c=word[:2] 
print ("c is: ") 
print (c) # index 0 and 1 elements of word. 
d=word[0:] 
print ("d is: ") 
print (d) # All elements of word. 
#元组可以合并 
e=word[:2]+word[2:] 
print ("e is: ") 
print (e) # All elements of word. 
f=word[-1] 
print ("f is: ") 
print (f) # The last elements of word. 
g=word[-4:-2] 
print ("g is: ") 
print (g) # index 3 and 4 elements of word. 
h=word[-2:] 
print ("h is: ") 
print (h) # The last two elements. 
i=word[:-2] 
print ("i is: ") 
print (i) # Everything except the last two characters 
l=len(word) 
print ("Length of word is: "+ str(l)) 
print ("Adds new element") 
word.append('h') 
print (word) 
#删除元素 
del word[0] 
print (word) 
del word[1:3] 
print (word) 
''' 

#! /usr/bin/python 
x={'a':'aaa','b':'bbb','c':12} 
print (x['a']) 
print (x['b']) 
print (x['c']) 
for key in x: 
print ("Key is %s and value is %s" % (key,x[key])) 
''' 

#! /usr/bin/python 
word="abcdefg" 
a=word[2] 
print ("a is: "+a) 
b=word[1:3] 
print ("b is: "+b) # index 1 and 2 elements of word. 
c=word[:2] 
print ("c is: "+c) # index 0 and 1 elements of word. 
d=word[0:] 
print ("d is: "+d) # All elements of word. 
e=word[:2]+word[2:] 
print ("e is: "+e) # All elements of word. 
f=word[-1] 
print ("f is: "+f) # The last elements of word. 
g=word[-4:-2] 
print ("g is: "+g) # index 3 and 4 elements of word. 
h=word[-2:] 
print ("h is: "+h) # The last two elements. 
i=word[:-2] 
print ("i is: "+i) # Everything except the last two characters 
l=len(word) 
print ("Length of word is: "+ str(l)) 

#! /usr/bin/python 
# -*- coding: utf8 -*- 
s=input("输入你的中文名,按回车继续"); 
print ("你的名字是 : " +s) 
l=len(s) 
print ("你中文名字的长度是:"+str(l)) 

#! /usr/bin/python 
#条件和循环语句 
x=int(input("Please enter an integer:")) 
if x<0: 
x=0 
print ("Negative changed to zero") 
elif x==0: 
print ("Zero") 
else: 
print ("More") 
# Loops List 
a = ['cat', 'window', 'defenestrate'] 
for x in a: 
print (x, len(x)) 
#知识点: 
# * 条件和循环语句 
# * 如何得到控制台输入 

#! /usr/bin/python 
# -*- coding: utf8 -*- 
def sum(a,b): 
return a+b 
func = sum 
r = func(5,6) 
print (r) 
# 提供默认值 
def add(a,b=2): 
return a+b 
r=add(1) 
print (r) 
r=add(1,5) 
print (r) 
一个好用的函数 
#! /usr/bin/python 
# -*- coding: utf8 -*- 
# The range() function 
a =range (1,10) 
for i in a: 
print (i) 
a = range(-2,-11,-3) # The 3rd parameter stands for step 
for i in a: 
print (i) 

#! /usr/bin/python 
s=input("Input your age:") 
if s =="": 
raise Exception("Input must no be empty.") 
try: 
i=int(s) 
except Exception as err: 
print(err) 
finally: # Clean up action 
print("Goodbye!") 

#! /usr/bin/python 
spath="D:/download/baa.txt" 
f=open(spath,"w") # Opens file for writing.Creates this file doesn't exist. 
f.write("First line 1.\n") 
f.writelines("First line 2.") 
f.close() 
f=open(spath,"r") # Opens file for reading 
for line in f: 
print("每一行的数据是:%s"%line) 
f.close() 

class Base: 
def __init__(self): 
self.data = [] 
def add(self, x): 
self.data.append(x) 
def addtwice(self, x): 
self.add(x) 
self.add(x) 
# Child extends Base 
class Child(Base): 
def plus(self,a,b): 
return a+b 
oChild =Child() 
oChild.add("str1") 
print (oChild.data) 
print (oChild.plus(2,3)) 
''' 
知识点: 
* self:类似Java的this参数 
''' 

# a.py 
def add_func(a,b): 
return a+b 
# b.py 
from a import add_func # Also can be : import a 
print ("Import add_func from module a") 
print ("Result of 1 plus 2 is: ") 
print (add_func(1,2)) # If using "import a" , then here should be "a.add_func" 

import sys 
import os 
sys.path.append(os.getcwd()+'\\parent\\child') 
print(sys.path) 
from a import add_func 
print (sys.path) 
print ("Import add_func from module a") 
print ("Result of 1 plus 2 is: ") 
print (add_func(1,2))