Validate the presence of a single string within another string

July 2, 2022

By using the following code I am trying to only keep the rows from the dataset that contain the value 9 within Col_B which is a string.

The issue is that by using this code it returns ONLY the rows that consist of ONLY the string "9",
while I want to also keep the rows that contain 9 amongst other strings.

Original input:

   Col_A        Col_B
0      5  1,2,9,0,6,4
1      2        3,1,0
2     46            0
3    184        1,5,7
4     31            9
5     81          9,0

Code used:

desired_numbers = ['9,', ',9', ',9,', '9']
df1 = df1[df1['Col_B'].isin(desired_numbers)]
df1

Original output:

   Col_A  Col_B
0     31      9

Desired output:

   Col_A        Col_B
0      5  1,2,9,0,6,4
1     31            9
2     81          9,0

Please let me know if you have any recommendations! Thanks

>Solution :

Try with string str.contains

out = df[df.Col_B.str.contains(r'\b9\b')] #str.match also work

Out[336]: 
   Index  Col_A        Col_B
0      0      5  1,2,9,0,6,4
4      4     31            9
5      5     81          9,0