Importing variables from a function inside another file-CodePudding

I'm trying to use a function from another file to generates random values for some variables but it doesn't seem to work

Function

def common_monsterstat():
  mattack = random.randint(1, 5)
  mdefense = random.randint(0, 1)
  mhealth = random.randint(5, 10)
  mmaxhealth = mhealth

Code that uses function (file name that function is in is named monsterstats.py)

from monsterstats import *

common_monsterstat()

def battlesys():
  print("You challenged Monster!")
  print("Monster's health: "   mhealth)

CodePudding user response：

You've got a problem with scope. When you create a function, every variable you assign a value to is a local variable (unless you use the global keyword). You could use the global keyword like this :

mhealth=0
def common_monsterstat():
   global mhealth
   mattack = random.randint(1, 5)
   mdefense = random.randint(0, 1)
   mhealth = random.randint(5, 10)
   mmaxhealth = health
def battlesys():
   print("You challenged Monster!")
   print("Monster's health: "   mhealth)
common_monsterstat()

This will make your code change the global health instead of creating a copy of it...

But the better way to do this is to simply return the health variable, because global keywords can become confusing after a while in my experience. However, if you need your game to be really efficient, which you probably don't, using global would save you from creating too many variables ( although not sure if it would be more efficient I just think so :)) So, you could do it like this:

def common_monsterstat():
      mattack = random.randint(1, 5)
      mdefense = random.randint(0, 1)
      mhealth = random.randint(5, 10)
      mmaxhealth = mhealth
      return mhealth
def battlesys():
  mhealth=common_monsterstat()
  print("You challenged Monster!")
  print("Monster's health: "   mhealth)
common_monsterstat()
battlesys()

This will create a localvariable, assign it a value, return it into another variable, and then print it... Seems more complex but is actually easier...

Tell me if you need any clarifications! PS: You might wanna have a random name for your monster and use an f-string to name in a cooler way:

monsters=['centaurus','dwarf','spider']
def battlesys():
   print(f"You challenged {r.choice(monsters)}!")
   print("Monster's health: "   health)

PPS: you didn't import random in your code...

CodePudding user response：

Inside the def common_monsterstat() function add a return statement for mmaxhealth. Then at the second code assign mhealth to common_monsterstat() function. I recommend u to learn about function, global and local variable at python :)

Here is the fix code:

def common_monsterstat():
  mattack = random.randint(1, 5)
  mdefense = random.randint(0, 1)
  mhealth = random.randint(5, 10)
  mmaxhealth = mhealth

  return mmaxhealth

from monsterstats import *

mhealth= common_monsterstat()

def battlesys():
  global mhealth

  print("You challenged Monster!")
  print("Monster's health: "   mhealth)

CodePudding user response：

If that's just setting up data, don't use a function. Yu can define constants that get imported by name. In "monsterstatps.py":

import random
mattack = random.randint(1, 5)
mdefense = random.randint(0, 1)
mhealth = random.randint(5, 10)

Then in your "main.py":

from monsterstats import *

def battlesys():
  print("You challenged Monster!")
  print("Monster's health: "   mhealth)

In the long term, you might define a class Stats that contains these values, and import an instance of that class.

CodePudding user response：

Instead of having all free floating variables, it might be easier to group them in a class. For example you can have a class for generic stats, and create a factory function that creates instances of that class.

class Stats:
    def __init__(self, attack, defense, health, maxhealth):
        self.attack = attack
        self.defense = defense
        self.health = health
        self.maxhealth = maxhealth


def common_monsterstat():
    mattack = random.randint(1, 5)
    mdefense = random.randint(0, 1)
    mhealth = random.randint(5, 10)
    mmaxhealth = mhealth
    
    return Stats(
        attack=mattack,
        defense=mdefense,
        health=mhealth,
        maxhealth=mmaxhealth,
    )

In the main method you can then use the factory method to retrieve the stats:

from monsterstats import *

stats = common_monsterstat()

def battlesys():
  print("You challenged Monster!")
  print("Monster's health: "   stats.health)

To make writing this class even easier, you could take advantage of a dataclass, which is perfect for pure data objects.

from dataclasses import dataclass

@dataclass
class Stats:
    attack: int
    defense: int
    health: int
    maxhealth: int

...