Using a dictionary to select function to execute

Question

I am trying to use functional programming to create a dictionary containing a key and a function to execute     myDict    myItems   P1   P2   P3       Pn   def myMain key       def ExecP1            pass     def ExecP2            pass     def ExecP3            pass                 def ExecPn            pass     Now  I have seen a code used to find the defined functions in a module  and I need to do something like this       for myitem in myItems          myDict myitem         to dynamically find the corresponding function   So my question is  How do I make a list of all the Exec functions and then assign them to the desired item using the a dictionary  so at the end I will have myDict  P1      this will call ExecP1    My real problem is that I have tons of those items and I making a library that will handle them so the final user only needs to call myMain  P1    I think using the inspect module  but I am not so sure how to do it   My reason to avoid   def ExecPn        pass myDict  Pn   ExecPn   is that I have to protect code as I am using it to provide a scripting feature within my application

User · Accepted Answer

Not proud of it  but   def myMain key       def ExecP1            pass     def ExecP2            pass     def ExecP3            pass     def ExecPn            pass      locals    Exec    key      I do however recommend that you put those in a module class whatever  this is truly horrible

User · Answer

You are wasting your time    You are about to write a lot of useless code and introduce new bugs  To execute the function  your user will need to know the P1 name anyway  Etc   etc   etc      Just put all your functions in the  py file     my module py  def f1        pass  def f2        pass  def f3        pass   And use them like this   import my module  my module f1   my module f2   my module f3     or   from my module import f1 from my module import f2 from my module import f3  f1   f2   f3     This should be enough for starters

User · Answer

class CallByName             def method1 self           pass      def method2 self           pass      def method3 self           pass      def get method self  method name           method   getattr self  method name          return method     callbyname   CallByName   method1   callbyname get method method name

User · Answer

index dictionary by list of key names  def fn1        print  One   def fn2        print  Two   def fn3        print  Three   fndict     A   fn1   B   fn2   C   fn3   keynames     A    B    C    fndict keynames 1        keynames 1     B   so output of this code is    Two

User · Answer

def p1         print  in p1    def p2        print  in p2    myDict        P1   p1       P2   p2     name input  enter P1 or P2     myDictname

User · Answer

Often classes are used to enclose methods and following is the extension for answers above with default method in case the method is not found    class P        def p1 self            print  Start         def p2 self            print  Help         def ps self            print  Settings         def d self            print  Default function         myDict               start   p1            help   p2            settings   ps              def call it self            name    start           f   lambda self  x   self myDict get x  lambda x   self d    self           f self  name     p   P    p call it

User · Answer

You can just use  myDict          P1    lambda x  function1          P2    lambda x  function2                   Pn    lambda x  functionn     myItems     P1    P2         Pn    for item in myItems      myDict item

User · Answer

This will call methods from dictionary  This is python switch statement with function calling  Create few modules as per the your requirement  If want to pass arguments then pass   Create a dictionary  which will call these modules as per requirement       def function 1 arg           print  In function 1        def function 2 arg           print  In function 2        def function 3 fileName           print  In function 3           f title f course1 f course2   fileName split              return f title f course1 f course2        def createDictionary             dict                  1   function 1              2   function 2              3   function 3                         return dict      dictionary   createDictionary       dictionary 3  Argument  pass any key value to call the method

User · Answer

usr bin python  def thing a arg None       print  thing a   arg  def thing b arg None       print  thing b   arg  ghetto switch statement          do thing a   thing a       do thing b   thing b    ghetto switch statement  do thing a    It s lovely being an A   ghetto switch statement  do thing b    Being a B isn t too shabby either    print  Available methods are     ghetto switch statement keys

User · Answer

Simplify  simplify  simplify   DRY   tasks      task   lambda f  tasks setdefault f   name    f    task def p1        whatever   task def p2        whatever  def my main key       tasks key

User · Answer

Simplify  simplify  simplify   def p1 args       whatever  def p2 more args       whatever  myDict          P1   p1       P2   p2               Pn   pn    def myMain name       myDict name      That s all you need     You might consider the use of dict get with a callable default if name refers to an invalid function     def myMain name       myDict get name  lambda   Invalid        Picked this neat trick up from Martijn Pieters

[python] Using a dictionary to select function to execute

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