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.
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.
If you are willing to add a decorator for each function, you can define a decorator which adds each function to a dictionary:
def myMain(key):
tasks = {}
def task(task_fn):
tasks[task_fn.__name__] = task_fn
@task
def ExecP1():
print(1)
@task
def ExecP2():
print(2)
@task
def ExecP3():
print(3)
@task
def ExecPn():
print(4)
tasks['Exec' + key]()
Another option is to place all the functions under a class (or in a different module) and use getattr
:
def myMain(key):
class Tasks:
def ExecP1():
print(1)
def ExecP2():
print(2)
def ExecP3():
print(3)
def ExecPn():
print(4)
task = getattr(Tasks, 'Exec' + key)
task()