20241206Class
# class Toy:
# head='blue'
# body='blue'
# def a():
# print('class internal function')
# toy1=Toy()
# print(toy1)
# Toy.a()
# class Toy:
# '''this is a toy class'''
# head='blue'
# body='blue'
# def a(self):
# print('class internal function')
# def __init_(self, leg):
# self.leg=leg
# toy1=Toy(2)
# print(Toy.__dict__)
# print(toy1.__dict__)
# print(toy1.a) #Toy.a
# print(toy1.a()) #Toy.a(toy1)
# toy1.x=10
# print(toy1.__dict__)
# toy2=Toy(4)
# print(toy2.__dict__)
#How python store data?
# #case 1 string look like identifier
# a='hello'
# b='hello'
# print(id(a))
# print(id(b))
# #case 3 long string but look like identifier
# a='hello_world'
# b='hello_world'
# print(id(a))
# print(id(b))
# #case 4
# a='_this_is_a _long_string_that_could_be_used_as_an_identifier'
# b='_this_is_a _long_string_that_could_be_used_as_an_identifier'
# print(id(a))
# print(id(b))
# #case 5
# a='1_hello_world'
# b='1 hello world'
# print(id(a))
# print(id(b))
# #case 6 not interned
# a='1 hello world'
# b='1 hello world'
# print(id(a))
# print(id(b))
# #case 7 interning strings
# a='this _is _a_long_string'
# b='this _is _a_long_string'
# print('a==b:', a==b)
# print('a is b:', a is b)
# #8 can't use is
# a='hello world'
# b='hello world'
# print('a==b:', a==b)
# print('a is b:', a is b)
# #9 force intern a, b must be set intern
# import sys
# a=sys.intern('hello world')
# b=sys.intern('hello world')
# c='hello world'
# print(id(a))
# print(id(b))
# print(id(c))
# #case 10 compare speed
# def compare_using_equals(n):
# a=sys.intern('a long string that is not interned' * 200)
# b=sys.intern('a long string that is not interned' * 200)
# for i in range(n):
# if a==b:
# pass
# def compare_using_interning(n):
# a=sys.intern('a long string that is not interned' * 200)
# b=sys.intern('a long string that is not interned' * 200)
# for i in range(n):
# if a is b:
# pass
# import time
# start=time.perf_counter()
# compare_using_equals(10000000)
# end=time.perf_counter()
# print('equality: ', end-start)
# start=time.perf_counter()
# compare_using_interning(10000000)
# end=time.perf_counter()
# print('interning: ', end-start)
##############################################
#Star-Argument
# def a(x, *arg):
# print('Hello World!', x, arg)
# a(1,2,3,4,5,6)
# def a(x,y, *arg):
# print('Hello World!', x, y, arg)
# def b(h,i):
# print(h,i)
# b(arg[0],arg[1])
# a(1,2,3,4,5,6)
#------------------------------------------------
# def a(x,y=1, *arg):
# print('Hello World!', x, y, arg)
# def b(h,i):
# print(h,i)
# b(arg[0], arg[1])
# a(1,2,3,4,5,6)
#-------------------------------------------------
# def a(x,y,z):
# print('a={1}, b={0}, c={2}'. format(x,y,z))
# a(1,2,3)
#--------------------------------------------------
# def a(x,y=2,z=3):
# print('a={1}, b={0}, c={2}'. format(x,y,z))
# a(1,2,3)
#keyword argument-----------------------------------
# def a(x,z, y=2):
# print('a={1}, b={0}, c={2}'. format(x,y,z))
# a(1,2,3)
#----------------------------------------------------
# def a(x,*arg, z=1, **kwarg):
# print(x, arg, kwarg)
# a(1,2,3,4,z,y=6)
# ans: 1(2,3.4) {'z':3, 'y':6}
#----------------------------------------------------
# def a(x,*arg, z=4, **kwarg):
# print(x, z,arg, kwarg)
# a(1,2,3,4,z=3,y=6)
# print(globals())
# #globals for scan all variable and value in function
# print(a.__str__)
#ans:1 3 (2, 3, 4) {'y': 6}
#------------------------------------------------------
def a(x,*arg, z=4, **kwarg):
print(x, z,arg, kwarg)
file(__name__=='__main__'): #for make sure the location of file while running
a(1,2,3,4,z=3,y=6)
print(globals())
#globals for scan all variable and value in function
print(a.__str__, a.__name__) #aINFO