Pandas -- search column for a string and classify them in a new column

Question

I have let's say following DF:

---

|Tweet|

|bla bla bad| 

|bla bla good|

---

From that I want to create something like:

---

|Tweet|           |Sentiment|

|bla bla bad|     |negative|

|bla bla good|    |positive|

---

I can search for string in a column with df[df['Tweet'].str.contains("bad|sad", na=False)] but how can I then create new column classifying them?

Thank you

Answer 1

Use numpy.where:

df['sentiment'] = np.where(df['Tweet'].str.contains('bad|sad'), 'negative', 'positive')
print(df)

Output

          Tweet sentiment
0   bla bla bad  negative
1  bla bla good  positive