I want to replace the start of a string (the first 5 characters) with nothing in column A if the value in Column B is equal to VendorA. I am not getting any further then replacing a value without the condition as mentioned above. 

I have tried the following code:

```
    ColumnA    Vendor
1    A          ABBC/1234
2    B          BCCD/1234           
3    B          1234
4    C          1234ABBC/

Dataset.ColumnA= Dataset.ColumnA.replace(regex=['ABBC/'], value='')

```

```
#This should be the output

    ColumnA    Vendor
1    A          1234
2    B          BCCD/1234           
3    B          1234
4    C          1234ABBC/

```