To plot ternary numbers which do not contain 1

plotnum.py

import matplotlib.pyplot as plt
import math as math

def get_exp(n):
  if n <= 0:
    return 0
  return math.floor(math.log(n, 3))

def conv_to_deci(n):
  s = str(n)
  l = len(s)
  res = 0
  for i in range(len(str(n))):
    res += (3 ** (l - 1 - i)) * int(s[i])
  return res

def test_conv_to_deci():
  i = [0, 1, 10, 20, 21, 10202]
  o = [0, 1, 3, 6, 7, 101]
  for p in range(len(i)):
    if conv_to_deci(i[p]) != o[p]:
      print('ng with ' + str(i[p]))

test_conv_to_deci()

tmp = []
for i in range(100):
  res = 0
  n = i
  while n > 2:
    idx1 = get_exp(n)
    res += 10 ** idx1
    n = n - 3 ** idx1
    if n > 0:
      idx2 = get_exp(n)
      res += 10 ** idx2
      n = n - 3 ** idx2
  res += n
  if ('1' in str(res)) == False:
    tmp.insert(len(tmp), res)

x = []
y = []
for el in tmp:
  num = conv_to_deci(el)
  x.insert(len(x), num)    
  y.insert(len(y), num)

plt.plot(x, y, 'o', color='black')
plt.title('Ternary Numbers which Do Not Contain 1')
plt.show()