Day04-python Basic Functions

A. Function objects: Functions are the first class of objects, that is, functions can be passed as data

1. Can be referenced

def foo ():     Print (' fromfoo') func=foo      ##foo值赋给了funcprint( Foo)    ##<function foo at 0x006e4108>print(func)   #  #<function foo at 0x006e4108>func ()        ##foo值赋给了func, so you can refer directly ()

2. Can be passed as parameters

def foo ():     Print ('fromfoo111111') def Bar (func):     Print (func)    func () bar (foo)

3. The return value can be a function

def foo ():     Print ('fromfoo') def Long (func):     return FUNCF=long (foo)print(f) f ()

4. Elements that can be used as container types

def foo ():     Print (' fromfoo'= {'fuck': foo}Print (dic['fuck') dic['fuck'] ()

defSelect (SQL):Print('------>select')defUpdate (SQL):Print('------>update')defDelete (SQL):Print('------>delete')defInsert (SQL):Print('------>insert') Fun_dit={    'Select': SELECT,'Update': Update,'Delete':d elete,'Insert': Insert}defMain (): whileTrue:sql= Input ('>>>:'). Strip ()if  notSql:ContinueL=sql.split () cmd=L[0]ifCmdinchFun_dit:fun_dit[cmd] (l) Main ()

Two. Nesting of functions

1. Nested calls to functions

def max2 (x, y    ): return if Else y def max4 (a,b,c,d):    res1=Max2 (A, b)    res2=max2 (res1,c)    res3=max2 ( res2,d)    return  res3print(max4 (10,80,31,20))

2. Function Nesting Definitions

def F1 ():     def F2 ():         Print ('fromfoo f2')         def f3 ():             Print ('fromfoo f3')        f3 ()    F2 () F1 ()

Day04-python Basic Functions