I have the following dataframe in pandas

```
  target   A       B      C
0 cat      bridge  cat    brush  
1 brush    dog     cat    shoe
2 bridge   cat     shoe   bridge

```

How do I test whether `df.target` is in any of the columns `['A','B','C', etc.]`, where there are many columns to check?

I have tried merging A,B and C into a string to use `df.abcstring.str.contains(df.target)` but this does not work.