python之内置函数与匿名函数
一内置函数
# print(abs(-1)) # print(all([1,2,'a',None])) # print(all([])) #bool值为假的情况:None,空,0,False # # print(any([])) # print(any([' ',None,False])) #True # print(any(['',None,False])) #False # print(any(['',None,False,1])) #True #bin,oct,hex # print(bin(10)) # print(oct(10)) # print(hex(10)) #bytes #unicode----encode----->bytes # print('hello'.encode('utf-8')) # print(bytes('hello',encoding='utf-8')) #callable # print(callable(bytes)) # print(callable(abs)) #chr,ord # print(chr(65)) # print(chr(90)) # print(ord('#')) #内置函数,又被称为工厂函数 # int # x=1 #x=int(1) # print(type(x)) # x=int(2) complex float str list tuple dict set #可变集合 frozenset #不可变集合 # s={1,2,3,4} #s=set({1,2,3,4}) # print(type(s)) # # s1=frozenset({1,2,3,4}) # print(type(s1)) #dir # import sys # # sys.path # # sys.argv # print(dir(sys)) #divmod # print(divmod(10,3)) # print(divmod(102,20)) #enumerate # l=['a','b','c'] # res=enumerate(l) # for i in res: # print(i) # for index,item in enumerate(l): # print(index,item) #globals,locals #查看全局作用域和局部作用域 # print(globals()) #hash # print(hash('abcdefg123')) # print(hash('abcdefg123')) # print(hash('abcdefg123')) # print(hash('abcdefg123')) #给函数加文档解释,用到单引号,双引号,三引号 def func(): # ''' # test function # :return: # ''' pass # print(help(func)) #id:是python解释器实现的功能,只是反映了变量在内存的地址 #但并不是真实的内存地址 # x=1 # print(id(x)) # def func():pass # print(id(func)) # print(func) #isinstance # x=1 # print(type(x) is int) # print(isinstance(x,int)) #x=int(1) #迭代器 iter next #len #max # print(max([1,2,3,10])) # print(max(['a','b'])) # print(min([1,2,3,10])) #pow # print(pow(3,2,2)) #3**2%2 #range # #repr,str # print(type(str(1))) # print(type(repr(1))) #reversed # l=[1,'a',2,'c'] # print(list(reversed(l))) # print(l) #slice # l=[1,2,3,4,5,6] # print(l[0:4:2]) # # s=slice(0,4,2) # print(l[s]) #sorted # l=[1,10,4,3,-1] # print(sorted(l,reverse=True)) #sum # print(sum([1, 2,3])) # # print(sum(i for i in range(10))) #vars # import m1 # print(vars(m1) == m1.__dict__) #zip:拉链 # s='hellosssssssssssssssss' # l=[1,2,3,4,5] # # print(list(zip(s,l))) #__import__ import sys # m_name=input('module>>: ') # if m_name == 'sys': # m=__import__(m_name) # print(m) # print(m.path) # # sys=__import__('sys') # print(sys) #round print(round(3.565,2)) print(round(3.555,2)) #filter,map,reduce 重点 #max min sorted #面向对象 object super # __dict__ isinstance issubclass classmethod staticmethod property delattr hasattr setattr getattr #了解 compile eval exec
二匿名函数
def func(x,y,z=1): return x+y+z # print(func) # print(func(1,2,3)) #匿名函数:1. 没有名字 2:函数体自带return # print(lambda x,y,z=1:x+y+z) f=lambda x,y,z=1:x+y+z print(f) print(f(1,2,3)) # x=1 # 1 # print(x) # print(1) #匿名函数的应用场景: #应用于一次性的场景,临时使用