Concatenate string and int

Question

I want to concatenate integer and string value, where integer is in a 2D list and string is in a 1D list.

['VDM', 'MDM', 'OM']

The above mentions list is my string list.

[[1, 2, 3, 4, 5], [1, 2, 3, 4, 5], [1, 2, 3, 4, 5]]

The above mentioned list is my integer list.

I have tried this code:

for i in range(numAttr):
    for j in range(5):
        abc=[[attr[i]+counts[i][j]]]
print(abc)

Here numAttr is the number of element in the first 1D list. and second 2D list is a static list i.e. for any dataset the 2D list will not change.

The above code showing the error:

TypeError: can only concatenate str (not "int") to str

I want a list output which looks like this:

[['VDM:1','VDM:2','VDM:3','VDM:4','VDM:5'],['MDM:1','MDM:2','MDM:3','MDM:4','MDM:5'],['OM:1','OM:2','OM:3','OM:4','OM:5']]

U12-Forward · Accepted Answer · 2019-06-10T09:56:17.610

2

Use the nested list comprehension below:

>>> l = ['VDM', 'MDM', 'OM']
>>> l2 = [[1, 2, 3, 4, 5], [1, 2, 3, 4, 5], [1, 2, 3, 4, 5]]
>>> [[a + ':' + str(b) for b in c] for a,c in zip(l, l2)]
[['VDM:1', 'VDM:2', 'VDM:3', 'VDM:4', 'VDM:5'], ['MDM:1', 'MDM:2', 'MDM:3', 'MDM:4', 'MDM:5'], ['OM:1', 'OM:2', 'OM:3', 'OM:4', 'OM:5']]
>>>

Or:

>>> l = ['VDM', 'MDM', 'OM']
>>> l2 = [[1, 2, 3, 4, 5], [1, 2, 3, 4, 5], [1, 2, 3, 4, 5]]
>>> [['{}:{}'.format(a, b) for b in c] for a,c in zip(l, l2)]
[['VDM:1', 'VDM:2', 'VDM:3', 'VDM:4', 'VDM:5'], ['MDM:1', 'MDM:2', 'MDM:3', 'MDM:4', 'MDM:5'], ['OM:1', 'OM:2', 'OM:3', 'OM:4', 'OM:5']]
>>>

Or:

>>> l = ['VDM', 'MDM', 'OM']
>>> l2 = [[1, 2, 3, 4, 5], [1, 2, 3, 4, 5], [1, 2, 3, 4, 5]]
>>> [['%s:%s' % (a, b) for b in c] for a,c in zip(l, l2)]
[['VDM:1', 'VDM:2', 'VDM:3', 'VDM:4', 'VDM:5'], ['MDM:1', 'MDM:2', 'MDM:3', 'MDM:4', 'MDM:5'], ['OM:1', 'OM:2', 'OM:3', 'OM:4', 'OM:5']]
>>>

Or f-strings (version >= 3.6):

>>> l = ['VDM', 'MDM', 'OM']
>>> l2 = [[1, 2, 3, 4, 5], [1, 2, 3, 4, 5], [1, 2, 3, 4, 5]]
>>> [[f'{a}:{b}' for b in c] for a,c in zip(l, l2)]
[['VDM:1', 'VDM:2', 'VDM:3', 'VDM:4', 'VDM:5'], ['MDM:1', 'MDM:2', 'MDM:3', 'MDM:4', 'MDM:5'], ['OM:1', 'OM:2', 'OM:3', 'OM:4', 'OM:5']]
>>>

edited Jun 10 '19 at 09:56

answered Jun 10 '19 at 08:03

U12-Forward

65,118
12
70
89

1

I prefer f-strings :D – Patrick Artner Jun 10 '19 at 08:07
1

@PatrickArtner Me too, just afraid that the OP will say, "it gives an error", since python < 3.6 doesn't work with f-strings, anyways will edit – U12-Forward Jun 10 '19 at 08:08
1

@PatrickArtner Haha i like how you format your deleted answer :P – U12-Forward Jun 10 '19 at 08:12
1

If not f-strings, then just: `[['{}:{}'.format(a, b)]...]` is fine... – Jon Clements Jun 10 '19 at 09:12
@JonClements Oh yeah – U12-Forward Jun 10 '19 at 09:55

score 0 · Answer 2 · answered Jun 10 '19 at 08:01

0

Change the line abc=[[attr[i]+counts[i][j]]] to abc=[[attr[i]+':'+str(counts[i][j])]]

answered Jun 10 '19 at 08:01

Carlos Gonzalez

778
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22

Concatenate string and int

2 Answers2