CODEWITHSUNDEEP
python-3.x
simkusr
simkusr

Reputation: 812

Pythonic way of creating if statement for nested if statements

I'm kind of newbie as programmer, but I wish to master Python and I'm developing open source application. This application has function to gather some information. This function takes 1 parameter. This parameter can be 0, 1 or 2. 0 = False, 1 = True, 2 = Multi. Also I have an if statement that does 2 actions. 1st - (when False) gathers single type value, 2nd - (when True) gathers multiple type values and when parameter is 2 (multi) then it will gather single type (1st) and multiple types (2nd). My if statement looks like this:

if False:
    get_single_type = code.of.action
    generators.generate_data(False, get_single_type)
elif True:
    get_multiple_type = code.of.action
    generators.generate_data(True, get_multiple_type)
else:
    get_single_type = code.of.action
    generators.generate_data(False, get_single_type)
    get_multiple_type = code.of.action
    generators.generate_data(True, get_multiple_type)

Is there maybe better way of avoiding this kind of coding, like in last else statement when I call both single and multiple.

Thank you in advance.

Upvotes: 1

Views: 1549

Answers (2)

r.ook
r.ook

Reputation: 13858

One thing I learned from Python is that although it lacks the Switch operator, you can use dictionary in a similar fashion to get things done since everything is an object:

def get_single():
    # define your single function
    get_single_type = code.of.action
    generators.generate_data(False, get_single_type)


def get_multi():
    # define your multi function
    get_multiple_type = code.of.action
    generators.generate_data(True, get_multiple_type)

actions = {
    0: [get_single],
    1: [get_multi],
    2: [get_single, get_multi]
}

parameter = 0 # replace this line with however you are capturing the parameter
for action in actions[parameter]:
    action()

This way you avoid c+p your code everywhere and have it referenced from the function, and your "actions" dictionary define the function to be used based on the parameter given.

In this case since you have multiple functions you want to call, I kept all dictionary items as a list so the structure is consistent and it can be iterated through to perform any number of actions.

Ensure you use leave out the () in the dictionary so that the functions aren't instantiated when the dictionary is defined. And remember to add () when you are actually calling the function from the dictionary to instantiate it.

Upvotes: 3

Joe Iddon
Joe Iddon

Reputation: 20414

This is something you will often encounter and it is pretty much always bad practice to be repeating code. Anyway, the way to do this is use two if-statements. This way, even if the first case passes, the second case can still pass. Oh, and assuming your variable that can be 0, 1 or 2 is called x, then we could either use or and two checks:

if x == 0 or x == 2:

but, personally, I prefer using in on a tuple:

if x in (0, 2):
    get_single_type = code.of.action
    generators.generate_data(False, get_single_type)
if x in (1, 2):
    get_multiple_type = code.of.action
    generators.generate_data(True, get_multiple_type)

Upvotes: 3

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