duplicate char pythonn code example

Example 1: double char python

def doubleChar(str):
  lisp = list(str)
  out = []
  string = ''
  for i in range(len(lisp)):
    out.append(lisp[i])
    out.append(lisp[i])
  for i in range(len(out)):
    string += out[i]
  return string

Example 2: check for double character in a string python

count = {}
for s in check_string:
  if s in count:
    count[s] += 1
  else:
    count[s] = 1

for key in count:
  if count[key] > 1:
    print key, count[key]