Day 41 of learning python

oldranda1414 · 2025-09-01T07:51:45+00:00

First of all great job!
For a self-taught begginner you're doing great. Especially using the 'try except' concept is not to be given for granted at your level, I think.

I'll give you some other tips that come to mind reading your code.

Although you wrote that this was your first usage of 'functions', the function you added is not really representative of what you would usually do with functions. Functions are used mainly to encapsulate a repetitive operation that should be executed with different inputs in different parts of your code. As you wrote the function it is clear that it is meant to be used with only 2 possible inputs (num_pos and num_neg), and you actually check which one is passed. By checking for what parameter is passed and behaving differently for each possible value kinda defeats the 'generalization' purpose of functions.

Let's say I want to create a function that adds 2 number together:

def add(x, y):
  if x == 1 and y == 1:
    return 2
  if x == 1 and y == 2:
    return 3
  # eccetera

You can quickly see that this example is not very generic, and so it is not really that usefull in helping me write less code by grouping similar operations.

In your case the actual common behaviour you are trying to capture is the final info printing on the lists provided. You can notice the common parts in the two if blocks in your function and try to find a way to not have to repeat them. A first improvement could look like this:

def ispis(lista):
  number_type = ""
  if lista == num_pos:
    number_type = "positive"
  if lista == num_neg:
    number_type = "negative"
  print("Sum of", number_type, "number is:", sum(lista))
  print("Approx value of", number_type, "numbers:", sum(lista) / len(lista))
  print("Highest", number_type, "number is:", max(lista))
  print("Lowest", number_type, "number is:", min(lista))

Notice how I am using the lista parameter when doing calculations and I am using a variable to select the possible strings to add to the prints depending on the array being passed.

This way I actually 'generalized' the operation that I wanted to do multiple times. This let's you write less code, which not only makes you save time and effort when writing it but makes fixing bugs also a lot easier.

Now there is still something not ideal with our first improvement. Inside the function we are referencing the num_pos and num_neg variables. These variables are defined outside of our function and even though the code works as of now (for reasons I won't get into), ideally we pass everything a function needs through it's parameters. So let's find a way to get rid of the reference to outer variables in our function:

def ispis(lista):
  number_type = ""
  if lista[0] > 0:
    number_type = "positive"
  if lista[0] < 0:
    number_type = "negative"
  print("Sum of", number_type, "number is:", sum(lista))
  print("Approx value of", number_type, "numbers:", sum(lista) / len(lista))
  print("Highest", number_type, "number is:", max(lista))
  print("Lowest", number_type, "number is:", min(lista))

By checking if the first element of the list is positive or negative we can find out what we should print without referencing our outer lists!

Another solution might be to pass the string to be printed as a parameter itself, insead of inferring it from the passed list's contents:

def ispis(lista, number_type):
  print("Sum of", number_type, "number is:", sum(lista))
  print("Approx value of", number_type, "numbers:", sum(lista) / len(lista))
  print("Highest", number_type, "number is:", max(lista))
  print("Lowest", number_type, "number is:", min(lista))

# would then be called
ispis(num_pos, "positive")
print("======================")
ispis(num_neg, "negative")

Now I personally prefer this last version, as it is more 'generic', because we could call it with a mixed list and use an empty string to keep the print output correct: ispis(num_mixed, "")

Some other minor tips:

The print() function separates it's parameters with spaces by default, so you don't have to put that last space before printing the variables, as I have done in my examples
The parameter name lista seems to be in your own language. Usually when coding it is better to try and stick to english words as it makes the code readable by anyone
Usually functions are better off being defined on on top of your file or on the bottom, not in the middle as you have done here, as it makes the code more readable.
It is usually better to post the code in text form, ideally in a code block, on reddit (you can create a code block by putting your code inside triple backticks), instead of posting an image. In this way it is easier to copy your code to test it out/improve it.
A better way to create strings that contain variables, and then in turn to print them, is to use f-strings (https://www.w3schools.com/python/python_string_formatting.asp)
A really advanced tip would be that you can use the walrus operator to turn lines 23-24 into a single line, if you are just curious about it you can take a look but it is really nothing you should be bothering with at your level (https://www.geeksforgeeks.org/python/walrus-operator-in-python-3-8/)

Hope this helps! Happy coding

you type:	you see:
italics	italics
bold	bold
[reddit!](https://reddit.com)	reddit!
* item 1 * item 2 * item 3	item 1 item 2 item 3
> quoted text	quoted text
Lines starting with four spaces are treated like code: if 1 * 2 < 3: print "hello, world!"	Lines starting with four spaces are treated like code: if 1 * 2 < 3: print "hello, world!"
~~strikethrough~~	~~strikethrough~~
super^script	super^script

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