Merging multiple def()

Python Help
1

Hi all,

Q: How would multiple def() be merged? For example:

x = int()
y = int()

def test(x,y):
    
    for x in range(2):
        for y in range(2):
            print('Hello World!')            
# test(x,y)

def test1(x,y):
    for x in range(2):
        for y in range(2):
            print('The world, hello!')
# test1(x,y)

Thanks.

2

What do you mean by ā€œmergedā€? What should happen when you use the ā€œmergedā€ resulting function, and how does that relate to what the original functions do?

3

Two def()s share the variables x and y. Iā€™d like to simplify the script while achieving the same result.

Edit:

ā€¦been testing this type of thingā€¦

x = int()
y = int()

def test(x,y):
    
    for x in range(2):
        for y in range(2):
            print('Hello World!')            
# test(x,y)

def test1(x,y):
    for x in range(2):
        for y in range(2):
            print('The world, hello!')
# test1(x,y)

keys = dict(var1 = test(x,y), var2 = test1(x,y))
keys['var1']
4

Just to make sure: you understand that right now, the code will completely ignore whatever is passed when you call the functions? And also that functions donā€™t share local variables (which includes parameters), ever? From Pythonā€™s perspective, the fact that both functions use the names x and y is completely coincidental and meaningless.

5

Yes. Thatā€™s the definition of function() in a more fundamental way.

Iā€™ll be back laterā€¦

6

Is this the reason?

a,b,c,d ā€¦=> z ā€˜OKā€™
z = a,b,c,d ā€˜NOT okā€™
a => z ā€˜OKā€™

ā€¦ this example violates the functionā€™s characteristics, thus they cannot be combined or shortened, correct?

x = int()
y = int()

def test(x,y):
    
    for x in range(2):
        for y in range(2):
            print('Hello World!')            
# test(x,y)

def test1(x,y):
for x in range(2):
for y in range(2):
            print('The world, hello!')
# test1(x,y)
7

In python it is not necessary to ā€œdeclareā€ variables, as is done is some other languages.

This is a complex way to write:

x = 0

That is because int() is short for int(0) that is 0.

Here the x and y parameters are ignored, did you think you must declare x and y before you use them in the for loops?

You can write it as this:

def test():  
    for x in range(2):
        for y in range(2):
            print('Hello World!')

Does this make sense?

2 Likes
8

Hello @Anno - I have to say I have never seen anyone tinkering with Python the way you doā€¦

Perhaps with ā€œmergingā€ you mean ā€œoverloadingā€?

from typing import overload

@overload
def test(x: int, y: int):
     ...   # this is the Ellipsis object written as "..."
@overload
def test(x: str, y: str):
    ....
def test(x, y):
    if isinstance(x, int) and isinstance(y, int):
        print(f"Hello world from two numbers who are now tightly merged: {x + y}")
    elif isinstance(x, str) and isinstance(y, str):
        print(f"Hello world from the strings `{x}` and `{y}` who are still separate")
    else:
        raise ValueError("Sorry, I can only test strings or ints")

But here you still need to write your own, single ā€˜testā€™ function that does all the work.

If you start from two given functions, test1 and test2, the only way to ā€œmergeā€ them (that I can think of) is to write yet another function, say either_test1_or_test2 that will call either test1 or test2 depending on whatever conditions are relevant:

def either_test1_or_test2(x, y):
    if x > 0 and y > 0:
        return test1(x, y)
    else:
        return test2(x, y)

There is another possible way of ā€œmergingā€. Perhaps you had this in mind?
You could call a function that takes another function as argument:

def test(func, *args):
    return func(*args)  # this is too simplistic too make practical sense, 
    # but is a pattern used for instance in functools.partial

Now you would have:

test(int, 42) == 42
test(str, 42) == "42"

test(test, int, 42) == 42
test(test, test, test, str, 42) == "42"
test(*(test, test, test, int, 42)) == 42
1 Like
9

@barry-scott @hansgeunsmeyer

Do you agree?

x for x inā€¦---------- is a set() ;
for x inā€¦----------- is undeclared ā€˜set()ā€™

def test():  
    for x in range(2):
        for y in range(2):
            print('Hello World!')

hmmā€¦
Do you call it a function? To me, itā€™s a set of {value1, value2,ā€¦}

So,

  1. ā€œdef test()ā€ is a function with the name ā€œtestā€ but no variables.

thinkingā€¦

So,

ā€¦test() and test(x,y) are simply different ways of writing the function. When using return(), perhaps the format should be something like test(value1, value2, value3,ā€¦) ----> Is it true?

10

No. Iā€™m sorry. In all respect, if I may make a suggestion, I would say: Buy a book. Any Python beginnerā€™s book is probably fine. Work through that, then come back with more questions. You need to first acquire a more basic understanding of programming in general. You cannot really get that in this forum, imo.

1 Like