How to access a specific variable created inside a function outside a function. Even when there are-CodePudding

I am new to programming and I am trying to teach myself. I am starting with python and I am struggling to figure out if I am going about this the right way. I am trying to figure out how to access a specific variable from inside a function outside of that function.

weight = input('Enter Amount: ')

def quantity():
  p_total = weight / 454
  print(f'Amount: {p_total}')
  
  hp_total = weight / 227
  print(f'Amount HP: {hp_total}')
  
  qp_total = weight / 114
  print(f'Amount QP: {qp_total}')

  return p_total, hp_total, qp_total

print(qp_total)

I want to then be able to access the individual variables created in there as needed. Such as being able to call just qp_total or p_total. Or would this not be a good use of a function? Again I am still extremely new to coding.

CodePudding user response：

As your result is a tuple, you can provide an index to retrieve the item you want from that tuple:

def quantity(weight):
    p_total = weight / 454
    hp_total = weight / 227
    qp_total = weight / 114
    return p_total, hp_total, qp_total

print(quantity(50)[2]) # 0.43859649122807015

If you want to have multiple items, but not the whole result, then you may use _ for the "empty" output (although technically not really "empty"):

p_total, _, qp_total = quantity(50)
print(p_total, qp_total) # 0.11013215859030837 0.43859649122807015

A concept like "accessing internal variables from outside" sounds more like pertaining to "class":

class Quantity():
    def __init__(self, weight):
        self.p_total = weight / 454
        self.hp_total = weight / 227
        self.qp_total = weight / 114

q = Quantity(50)
print(q.qp_total) # 0.43859649122807015

But in my opinion, it is an overcomplication in this case.

CodePudding user response：

You never actually call your quantity function. Plus you should really pass the weight variable in:

def quantity(weight):
  p_total = weight / 454
  print(f'Amount: {p_total}')
  
  hp_total = weight / 227
  print(f'Amount HP: {hp_total}')
  
  qp_total = weight / 114
  print(f'Amount QP: {qp_total}')

  return p_total, hp_total, qp_total

weight = input('Enter Amount: ')
p_total, hp_total, qp_total = quantity(weight)
print(qp_total)

CodePudding user response：

def quantity(weight):
  p_total = weight / 454
  hp_total = weight / 227
  qp_total = weight / 114
  return p_total, hp_total, qp_total

weight = int(input('Enter Amount: '))
p_total = quantity(weight)[0]
hp_total = quantity(weight)[1]
qp_total = quantity(weight)[2]
print(qp_total)

The weight input must be converted to an integer because in python the input is passed as a string.