How to Merge Values from Some Columns in Python

Question

I have a dataframe in Python below:

import pandas as pd
df = pd.DataFrame({
    'CRDACCT_DLQ_CYC_1_MNTH_AGO' : [3, 2, 'C', 'C', 'C', 'C', 'C', 'C', 'C', 'C', 'C', 'C', 'C', 'C', 'C', 'C', 'C', 'C', 'C', 'C', 'C', 'C', 'C', 'C'], 
    'CRDACCT_DLQ_CYC_2_MNTH_AGO': [4, 3, 3, 3, 3, 3, 2, 0, 5, 4, 3, 2, 0, 2, 2, 2, 2, 2, 2, 0, 2, 2, 0, 2], 
    'CRDACCT_DLQ_CYC_3_MNTH_AGO': [8, 7, 6, 5, 4, 3, 2, 'F', 'F', 0, 'C', 'C', 'C', 'C', 'C', 'C', 'C', 'C', 'C', 'F', 'C', 'C', 'F', 'F'], 
    'CRDACCT_DLQ_CYC_4_MNTH_AGO' : [0, 2, 'F', 'F', 'C', 'C', 'C', 'C', 0, 2, 0, 2, 0, 2, 'C', 'C', 'C', 'C', 'C', 'C', 'C', 'F', 'C', 'F'], 
    'CRDACCT_DLQ_CYC_5_MNTH_AGO' : [2, 2, 'C', 'C', 'C', 'C', 'C', 'C', 'C', 'C', 'C', 'C', 'C', 'C', 'C', 'C', 'C', 'C', 'C', 'C', 'C', 'C', 'C', 'C'], 
    'CRDACCT_DLQ_CYC_6_MNTH_AGO' : [2, 2, 2, 'C', 'C', 'C', 'C', 'C', 'C', 'C', 'C', 'C', 'C', 'C', 'C', 'C', 'C', 'C', 'C', 0, 2, 0, 2, 0], 
    'CRDACCT_DLQ_CYC_7_MNTH_AGO' : [3, 3, 2, 'C', 'C', 'C', 'F', 0, 6, 5, 4, 3, 2, 2, 'C', 'C', 'C', 'C', 'C', 'C', 'C', 'C', 'C', 'C'], 
    'CRDACCT_DLQ_CYC_8_MNTH_AGO' : [5, 4, 4, 3, 3, 2, 3, 2, 2, 2, 1, 2, 0, 2, 'C', 'C', 0, 2, 2, 2, 'C', 'C', 0, 'Z'], 
    'CRDACCT_DLQ_CYC_9_MNTH_AGO' : [2, 2, 'C', 0, 2, 0, 2, 'C', 'C', 'C', 'C', 'C', 0, 3, 2, 'C', 'F', 'C', 'F', 'F', 'F', 'F', 'F', 'F'], 
    'CRDACCT_DLQ_CYC_10_MNTH_AGO' : [5, 4, 3, 2, 3, 2, 0, 2, 0, 2, 'C', 'C', 'F', 2, 'F', 'F', 'F', 'F', 'F', 'F', 'F', 'F', 'F', 'C'], 
    'CRDACCT_DLQ_CYC_11_MNTH_AGO' : [4, 3, 2, 'F', 2, 0, 'Z', 'Z', 'Z', 'Z', 'Z', 'Z', 'Z', 'Z', 'Z', 'Z', 'Z', 'Z', 'Z', 'Z', 'Z', 'Z', 'Z', 'Z'], 
    'CRDACCT_DLQ_CYC_12_MNTH_AGO' : ['F', 8, 7, 6, 5, 4, 3, 2, 'C', 'C', 'C', 0, 2, 'C', 'C', 0, 2, 0, 3, 2, 'C', 'C', 'F', 2]
})

df.head()

I want to create a new column that consists merging values of CRDACCT_DLQ_CYC_1_MNTH_AGO, CRDACCT_DLQ_CYC_2_MNTH_AGO, ....., CRDACCT_DLQ_CYC_12_MNTH_AGO. Let's say that new column named as HISTORY_DLQ.

If I print that new column, the expected result looks like this :

print(df['HISTORY_DLQ'])

#Output consists 24 rows of merging values of each column CRDACCT_DLQ_CYC_1_MNTH_AGO,..., CRDACCT_DLQ_CYC_12_MNTH_AGO.
[34802235254F,237222342438, C36FC224C327,...,C2FFC0CZFCZ2]

Answer 1

Convert your columns to string then join each row of columns:

df['HISTORY_DLQ'] = df.astype(str).apply(''.join, axis=1)
print(df['HISTORY_DLQ'])

# Output:
0     34802235254F
1     237222342438
2     C36FC224C327
3     C35FCCC302F6
4     C34CCCC32325
5     C33CCCC20204
6     C22CCCF320Z3
7     C0FCCC02C2Z2
8     C5F0CC62C0ZC
9     C402CC52C2ZC
10    C3C0CC41CCZC
11    C2C2CC32CCZ0
12    C0C0CC200FZ2
13    C2C2CC2232ZC
14    C2CCCCCC2FZC
15    C2CCCCCCCFZ0
16    C2CCCCC0FFZ2
17    C2CCCCC2CFZ0
18    C2CCCCC2FFZ3
19    C0FCC0C2FFZ2
20    C2CCC2CCFFZC
21    C2CFC0CCFFZC
22    C0FCC2C0FFZF
23    C2FFC0CZFCZ2
dtype: object

Answer 2

You can convert the columns to strings, then concat the strings on each row across columns using .sum() , as follows:

df['HISTORY_DLQ'] = df.astype(str).sum(axis=1)

.sum() on strings is like what you do to 'abc' + 'def' and will concat the strings to become 'abcdef' . When using it on axis=1 , it works on each row across the columns. Thus, achieving the result we want.

If your dataframe contains other columns that you don't want to merge their values, you can filter only the related columns by .filter() before we apply the logics above:

df['HISTORY_DLQ'] = df.filter(regex=r'CRDACCT_DLQ_CYC_\d+_MNTH_AGO').astype(str).sum(axis=1)

Here, we filter with regex r'CRDACCT_DLQ_CYC_\\d+_MNTH_AGO' for column names that starts with CRDACCT_DLQ_CYC_ followed by one or more digits \\d+ , then followed by _MNTH_AGO for the 12 columns.

Result:

print(df['HISTORY_DLQ'])

0     34802235254F
1     237222342438
2     C36FC224C327
3     C35FCCC302F6
4     C34CCCC32325
5     C33CCCC20204
6     C22CCCF320Z3
7     C0FCCC02C2Z2
8     C5F0CC62C0ZC
9     C402CC52C2ZC
10    C3C0CC41CCZC
11    C2C2CC32CCZ0
12    C0C0CC200FZ2
13    C2C2CC2232ZC
14    C2CCCCCC2FZC
15    C2CCCCCCCFZ0
16    C2CCCCC0FFZ2
17    C2CCCCC2CFZ0
18    C2CCCCC2FFZ3
19    C0FCC0C2FFZ2
20    C2CCC2CCFFZC
21    C2CFC0CCFFZC
22    C0FCC2C0FFZF
23    C2FFC0CZFCZ2
Name: HISTORY_DLQ, dtype: object