Aligning two strings: Bigramm/Buble

Question

I am try to write a function that allows me to line up two strings if the characters in both strings match.

for example Input:

output:

['H', 'o', 'u', 's', 'e'] ['H', 'o', 's']

desired output:

['H', 'o', 'u', 's', 'e'] 
['H', 'o', ,'0','s', '0']

I was thinking of doing this with something like bubble sort or using bigrams, but I don't have any experience with those. Does anyone have any suggestions ?

Answer 1

Quick and dirty approach:

l1 = ['H', 'o', 'u', 's', 'e'] 
l2 = ['H', 'o', 's']

l2, l1 = sorted((l1, l2), key=len)
l = len(l1)
j = 0

res = []
for i in range(l):
  try:
    if l1[i]==l2[j]:
      res.append(l1[i])
      j += 1
    else:
      res.append(None)    
  except IndexError:
    res.extend([None] * (l-j))
    break

print(res)  # -> ['H', 'o', None, 's', None]

Note that clarifications are needed! (see @yatu's comment)

Also note that I changed your '0' to None. Using '0' is a bad idea since, at least in theory, your two initial lists might contain that and you will not be able to differentiate between a match and a non-match.

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I am definitely looking forward to a more elegant approach to this interesting problem!