Learn python the hard way ex24

Question

I don't understand why beans, jars, crates = secret_formula(start_point) refers to jelly_beans, jars, crates .

This is the Ex24 from Learn python the hard way. Below I will put a answer from a Stackoverflow question with almost the same answer but didn't explain it fully so I really have a grasp of it.

print "Let's practice everything."

print 'You\'d need to know \'bout escape with \\ that do \n newlines and \t tabs.' 

poem = """ \tThe lovely world with logic so firmly planted cannot discern \n the needs of love nor comprehend passion from intuition and requires an explanation \n\t\twhere there is none. """

print "-------------"
print poem
print "-------------" 

five = 10 - 2 + 3 - 6

print "This should be five: %s" % five 

def secret_formula(started):
    jelly_beans = started * 500 
    jars = jelly_beans / 1000 
    crates = jars / 100 
    return jelly_beans, jars, crates 

start_point = 10000

beans, jars, crates = secret_formula(start_point)

print "With a starting point of : %d" % start_point
print "We'd have %d beans, %d jars, and %d crates." % (beans, jars, crates) 

start_point = start_point / 10 

print "We can also do that this way:"

print "We'd have %d beans, %d jars, and %d crates." % secret_formula(start_point)

This is the answer I found elsewhere:

Learn Python the Hard Way - Exercise 24

Due to the scoping rules of Python, the name jelly_beans is valid only inside the secret_formula function. That is the reason you can not refer to it via a statement like print jelly_beans outside the function. Notice that secret_formula returns a tuple to its caller. Therefore, when you type: beans, jars, crates = secret_formula(start_point) you specify a call to secret_formula (with a certain parameter), and assign the contents of the tuple to three different names.

• the returned value of jelly_beans is assigned to beans
• the returned value of jars is assigned to jars
• the returned value of crates is assigned to crates

Q: Why can't we call beans jelly_beans? Why can we with jars and crates?

I do understand that we get to 50000 by multiplying started * 1000.

However, why do we get that answer at:

print "We can also do that this way:"
print "We'd have %d beans, %d jars, and %d crates." % secret_formula(start_point)

Answer 1

Why can't we call beans jelly_beans? Why can we with jars and crates?

It is not true. you can call your variable whatever you want, even jelly_beans.

jelly_beans, jars, crates = secret_formula(10000)

but have it in mind that these variable have nothing to do with those inside your function.

BEST Way to learn is to do it.