partial.py

"""
computing partial sums 
for a multiplication
"""


def updict(v,p,d):
  if p in d:
    d[p].append(v)
  else:
    d[p] = [v]
  return(d)
  
def computedict(d):
  ret = []
  carry = 0
  for p in sorted(d.keys()):
    thisValue = sum(d[p]) + carry
    digit = thisValue % 10
    ret.append(str(digit))
    carry = (thisValue - digit) // 10
  if carry>0:
    ret.append(str(carry))
    
  return(''.join(reversed(ret)))
  

strinputa = input()
strinputb = input()
resultLen = len(strinputb) + len(strinputa) + 1
print(strinputa.rjust(resultLen))
print(('x'+strinputb).rjust(resultLen))
print('-'*resultLen)
partialSums = {}
for i,x in enumerate(reversed(strinputb)):
  try:
    intx = int(x)
    digitSum = {}
    for j,y in enumerate(reversed(strinputa)):
      inty = int(y)
      print(str(intx*inty).rjust(resultLen-(i+j)))
      partialSums = updict(intx*inty,i+j,partialSums)
      digitSum = updict(intx*inty,i+j,digitSum)
    digitRes = computedict(digitSum)
    print('-'*resultLen)
    print(digitRes.rjust(resultLen-i)+i*'0')
    print('-'*resultLen)
  except ValueError:
    print('Give positive integers')
result = computedict(partialSums)
print(result.rjust(resultLen))