Python基础（下）

1 print("\n".join([''.join(['*'*((x-y)%3) if((x*0.05)**2+(y*0.1)**2 -1)**3-(x*0.05)**2*(y*0.1)**3<=0 else ' ' for x in range(-30,30)]) for y in range(15,-15,-1)]))

1 def 函数名():
2     此函数做的事情1
3     此函数做的事情3
4     此函数做的事情2
5     ...省略...

1 def addition():#定义函数
2     a = 2
3     b = 3
4     c = a + b
5     print(c)
6 addition()#调用函数

1 def addition():#定义函数
2     '两个数字求和'
3     a = 2
4     b = 3
5     c = a + b
6     print(c)
7 addition()#调用函数

1 def addition(a,b):#定义带入参数的函数
2     '两个数字求和'
3     c = a + b
4     print(c)
5 addition(2,3)#调用带入参数的函数

1 def addition(a,b):#定义函数
2     '两个数字求和'
3     c = a + b
4     return c
5 result = addition(2,3)#调用函数
6 print(result)

1 def addition(a,b):
2     return a+1,b+1
3 result = addition(2,3)
4 print(result)

1 def addition(a,b=3):
2     return a+1,b+1
3 result = addition(2)
4 print(result)

1 def addition(a,b,*arg):
2     print(a)
3     print(b)
4     print(arg)
5 addition(1,2,3,4,5,6)

1 def addition(a,b,**kwargs):
2     print(a)
3     print(b)
4     print(kwargs)
5 addition(1,2,name='jonins',age='18')

 1 def addition(a,b,c=3,*args,**kwargs):
 2     print(a)
 3     print(b)
 4     print(c)
 5     print(args)
 6     print(kwargs)
 7 print('--------2个必填参数---------')
 8 addition(1,2)
 9 print('-------2个必填1个缺省其它为不定长*args----------')
10 addition(1,2,3,4)
11 print('-------2个必填1个缺省其它为不定长**kwargs----------')
12 addition(1,2,name = 'jonins',age = '18')
13 print('-------2个必填1个缺省有不定长*args和**kwargs----------')
14 addition(1,2,3,4,5,6,name = 'jonins',age = '18')

1 def addition(a,b,*args,**kwargs):
2     print(a)
3     print(b)
4     print(args)
5     print(kwargs)
6 A = {1,2,3,4}
7 B = {"name":"jonins","age":18}
8 addition(1,2,A,B)

1 def addition(a,b,*args,**kwargs):
2     print(a)
3     print(b)
4     print(args)
5     print(kwargs)
6 A = {1,2,3,4}
7 B = {"name":"jonins","age":18}
8 addition(1,2,*A,**B)

 1 a = 100
 2 def test1():
 3     print('test1,%i' % a)
 4 def test2():
 5     print('test2,%i' % a)
 6 def test3():
 7     a = 200
 8     print('test3,%i' % a)
 9 def test4():
10     global a
11     a = 200
12     print('test4,%i' % a)
13 test1()
14 test2()
15 test3()
16 print('未使用global时，全局变量外部为:%i'%a)
17 test4()
18 print('使用global时，全局变量外部为:%i'%a)

1 a=100
2 b=a
3 c=b
4 print(id(a))
5 print(id(b))
6 print(id(c))

1 A = ['1','2','3','4']
2 B = A
3 A.append('5')
4 print(B)
5 a = 100
6 b = a
7 a = 200
8 print(b)

1 a = 100
2 b = a
3 print(id(a))
4 print(id(b))
5 a = 200
6 print('--修改值后--')
7 print(id(a))
8 print(id(b))

1 class CSharpCoder(): #定义类、经典类方式定义
2     'C#程序员' #CSharpCoder类的描述信息
3     pass
4 class PythonCoder(object): #定义类、新式类方式定义
5     'Python程序员' #PythonCoder类的描述信息
6     pass
7 cp_cder = CSharpCoder() #实现CSharpCoder类的对象
8 py_cder = PythonCoder() #实现PythonCoder类的对象

1 class CSharpCoder():
2     name = ''
3 cp_cder = CSharpCoder()
4 cp_cder.name = 'Jonins'
5 print(cp_cder.name)

1 class CSharpCoder():
2     name = 'k'
3     def get_name(self):
4         print(self.name)
5 cp_cder = CSharpCoder()
6 cp_cder.name = 'Jonins'
7 cp_cder.get_name()

 1 class CSharpCoder():
 2     name = 'k'
 3     def  __init__(self,name):
 4         print('实例化对象中...')
 5         self.age = 18
 6         self.name = name
 7     def get(self):
 8         print(self.age)
 9         print(self.name)
10 cp_cder = CSharpCoder('Jonins')
11 cp_cder.get()

1 class CSharpCoder():
2     def  __init__(self):
3         print('实例化对象中...')
4     def __del__(self):
5         print('释放对象中...')
6 cp_cder = CSharpCoder()
7 del cp_cder #删除对象