why is the dcount and tcount 0 and 0 in the output

Question

Why are the dcount and tcount 0 and 0 in the output?

a = [1, 2, 3, 4]
dcount = 0
tcount = 0
def doubles():
  dcount = 0
  for i in a:
    for j in a:
      if (i+j)%3 == 0:
        dcount += 1
        print(i,j)

def triplets():
  tcount = 0
  for i in a:
    for j in a:
      for k in a:
        
        if (i+j+k)%3 == 0:
          tcount += 1
          print(i,j,k)

doubles()
triplets()
print(dcount)
print(tcount)

4 1 4
4 2 3
4 3 2
4 4 1
4 4 4
0
0
[Finished in 0.1s]

Answer 1

Because the dcount and tcount variables you use inside the functions aren't the same as the one on outside.

There's two ways:
1) you can just return the values and store it inside dcount instead of declaring it.

def doubles():
     //blah blah
     return dcount

dcount = doubles()

2) use global variables (not recommended) 

def triplets():
    global tcount 
    // blah blah

If the same names confuses you, you can use another name:

def doubles():
     doubles_count = 0
     //blah blah
     return doubles_count

dcount = doubles()