pandas: apply random.shuffle() to list column

April 28, 2022

I have a dataframe as follows,

import pandas as pd
df= pd.DataFrame({'text':['The weather is nice','the house is amazing','the flowers are blooming']})

I would like to shuffle the words in each row using random.shuffle(),(e.g the new first row will be ‘nice is weather the’ ),so I have done the following,

df.new_text = df.text.str.split()

and tried to map or apply shuffle() function but it returns None.

print(df.new_text.map(lambda x: random.shuffle(x)))

print(df.new_text.apply(lambda x: random.shuffle(x)))

I am not sure what I am doing wrong here. and then finally I would like to join the shuffled words in the list to get a string per row,

df.new_text = df.new_text.apply( lambda x:' '.join(x))

>Solution :

This does the job.

shuffled_sentences = {"text":[]}

for sentence in df.values.ravel():
  np.random.shuffle(sentence)
  shuffled_sentences["text"].append(sentence)

shuffled_df = pd.DataFrame(shuffled_sentences)

The thing with np.random.shuffle is that it doesn’t return any output. So you need to store the list you want to shuffle in a vraible first. Then if you apply np.random.shuffle on it, the original variable itself would be shuffled.