Create list of words and group them by index

I have column of index and each index has it’s corresponding word:

id word
1 word1
1 word2
1 word3
2 word4
2 word5

and so on.

I want to group them by index in this way: for id 1-[word1,word2,word3] for id 2-[word4,word5]

and so on

and extract to CSV file

I have this code:

df = pd.DataFrame(data)
d={"word":"first"}
df_new = df.groupby(df['id'], as_index=False).aggregate(d).reindex(columns=df['word'])
print (df_new)

df_new.to_csv('test.csv', sep='t', encoding='utf-8', index=False)    

What do I need to change in order for that to work?

Thank you in advance

Answer

# Import Dependencies
import pandas as pd

# Create DataFrame
data = {'id': [1, 1, 1, 2, 2], 'word': ['word1', 'word2', 'word3', 'word4', 'word5']}
df = pd.DataFrame(data)

# Groupby and Merge
df = df.groupby('id', as_index=False).agg({'word' : ','.join})  
# Result

    id  word
0   1   word1,word2,word3
1   2   word4,word5