How to fix dictionary error with same keys having different values

I have a text file with lines having two columns (separated by a Tab). I want to open this file and have as output a dictionary, store the 1st column as keys, then the 2nd column as values. But I am difficulty handling keys that have different values (like Camiguin below):

<pre>
Sandingan Loon, Bohol
Pangangan Calape, Bohol
Limasawa Limasawa, Southern Leyte
Catalat San Vicente, Palawan
Camiguin Catarman, Camiguin
Camiguin Guinsiliban, Camiguin
Camiguin Mahinog, Camiguin
Camiguin Mambajao, Camiguin
Camiguin Sagay, Camiguin
Rasa Narra, Palawan
</pre>

The code I used is:

filesDir = "C:\Users\user\Desktop"

fhand = open(filesDir+"\input.txt")
fout = open(filesDir+"output.txt","w")

d = dict()

for line in fhand:
  x = line.rstrip("\n")
  x = x.split("\t")

  if x[0] not in d:
    d[x[0]] = x[1]
	
  else:
    d[x[0]] += x[1]
    continue

print(d)

The result I am getting is this (note the result for Camiguin which simply concatenated the values together. I probably would need to use a list, but I cannot figure how to):

{'Limasawa': 'Limasawa, Southern Leyte', 'Rasa': 'Narra, Palawan', 'Catalat': 'San Vicente, Palawan', 'Camiguin': 'Catarman, CamiguinGuinsiliban, CamiguinMahinog, CamiguinMambajao, CamiguinSagay, Camiguin', 'Pangangan': 'Calape, Bohol', 'Sandingan': 'Loon, Bohol'}

EDIT: My desired output should be something like this:

{'Limasawa': 'Limasawa, Southern Leyte', 'Rasa': 'Narra, Palawan', 'Catalat': 'San Vicente, Palawan', 'Camiguin': ['Catarman, Camiguin','Guinsiliban, Camiguin','Mahinog, Camiguin','Mambajao, Camiguin','Sagay, Camiguin'], 'Pangangan': 'Calape, Bohol', 'Sandingan': 'Loon, Bohol'}

Instead of using a dictionary, use a defaultdict, then you can always append

from collections import defaultdict
d = defaultdict(list)

for line in fhand:
  x = line.rstrip("\n")
  x = x.split("\t")
  d[x[0]].append(x[1])

print(d)

Using dict.setdefault

Ex:

res = {}
with open(filename) as infile:
    for line in infile:
        key, value = line.strip().split("\t")    #Get key-value from line
        res.setdefault(key, []).append(value)    #Use list to append values. 
print(res)

Output:

{'Camiguin': ['Catarman, Camiguin',
              'Guinsiliban, Camiguin',
              'Mahinog, Camiguin',
              'Mambajao, Camiguin',
              'Sagay, Camiguin'],
 'Catalat San': ['Vicente, Palawan'],
 'Limasawa': ['Limasawa, Southern Leyte'],
 'Pangangan': ['Calape, Bohol'],
 'Rasa': ['Narra, Palawan'],
 'Sandingan': ['Loon, Bohol']}

Under your else loop, you can check the type of the value assigned to that key. If the type is a string, replace it with a list containing the current string and the new value. If the value is already a list, append the new value to it.

  else:
    if type(d[x]) == 'str':
      d[x] = [d[x], x[1]]
    elif type(d[x] == 'list'):
      d[x].append(x[1])