In case your input is a string, you just have to use the string's .split method to split it into a list:
>>> original_string = "'ACC': 2, 'ACACAGTTTGCGCGCGCGGGG': 1, 'ACCGTA': 3, 'GCTTTAAAAAGGCAA': 1, 'ACCGTAACCTTG': 2"
>>> splitted = original_string.split(', ')
>>> splitted
["'ACC': 2",
"'ACACAGTTTGCGCGCGCGGGG': 1",
"'ACCGTA': 3",
"'GCTTTAAAAAGGCAA': 1",
"'ACCGTAACCTTG': 2"]
>>> for el in splitted:
print el + ','
'ACC': 2,
'ACACAGTTTGCGCGCGCGGGG': 1,
'ACCGTA': 3,
'GCTTTAAAAAGGCAA': 1,
'ACCGTAACCTTG': 2,
However, I suspect that you just want to print the contents of a dictionary in order to see them more clearly. If that is the case, have a look at the pprint function:
>>> import pprint
>>> mydict = {'ACC': 2, 'ACACAGTTTGCGCGCGCGGGG': 1, 'ACCGTA': 3, 'GCTTTAAAAAGGCAA': 1, 'ACCGTAACCTTG': 2}
>>> pprint.pprint(mydict)
{'ACACAGTTTGCGCGCGCGGGG': 1,
'ACC': 2,
'ACCGTA': 3,
'ACCGTAACCTTG': 2,
'GCTTTAAAAAGGCAA': 1}
Also, consider using ipython instead of the standard python interpreter, which has many features and pretty-prints dictionaries by default.
Note that by accident it seems that you included the same output in for both input and output, please edit your question and change that.