df[]

df[condition]

Creates a new dataframe containing only the rows that satisfy a specific condition.

Input:

condition : bool

A sequence of boolean values with length equal to the number of rows of the DataFrame.

Returns:

new_df - A new DataFrame that contains only the rows whose corresponding element in condition is True.

Return Type:

DataFrame

---

pets

Index	ID	Species	Color	Weight	Age	Is_Cat	Owner_Comment
0	dog_001	dog	black	40	5	False	There are no bad dogs, only bad owners.
1	cat_001	cat	golden	1.5	0.2	True	My best birthday present ever!!!
2	cat_002	cat	black	15	9	True	****All you need is love and a cat.****
3	dog_002	dog	white	80	2	False	Love is a wet nose and a wagging tail.
4	dog_003	dog	black	25	0.5	False	Be the person your dog thinks you are.
5	ham_001	hamster	black	1	3	False	No, thank you!
6	ham_002	hamster	golden	0.25	0.2	False	No, thank you!
7	cat_003	cat	black	10	0	True	No, thank you!

Series of bools of if Species is a dog AND Color is white

(pets.get('Species')=='dog') & (pets.get('Color')=='white')

• 0False
• 1False
• 2False
• 3True
• 4False
• 5False
• 6False
• 7False

Name: Species is a dog AND color is white, dtype: Unknown type

DataFrame where Species is a dog AND Color is white

pets[(pets.get('Species')=='dog') & (pets.get('Color')=='white')]

Index	ID	Species	Color	Weight	Age	Is_Cat	Owner_Comment
3	dog_002	dog	white	80	2	False	Love is a wet nose and a wagging tail.

Series of bools where Species is a dog OR Color is white

(pets.get('Species')=='dog') | (pets.get('Color')=='white')

• 0True
• 1False
• 2False
• 3True
• 4True
• 5False
• 6False
• 7False

Name: Species is a dog OR color is white, dtype: Unknown type

DataFrame where Species is a dog OR Color is white

pets[(pets.get('Species')=='dog') | (pets.get('Color')=='white')]

Index	ID	Species	Color	Weight	Age	Is_Cat	Owner_Comment
0	dog_001	dog	black	40	5	False	There are no bad dogs, only bad owners.
3	dog_002	dog	white	80	2	False	Love is a wet nose and a wagging tail.
4	dog_003	dog	black	25	0.5	False	Be the person your dog thinks you are.

Some other examples!

pets[pets.get('Weight') >= 25]

Index	ID	Species	Color	Weight	Age	Is_Cat	Owner_Comment
0	dog_001	dog	black	40	5	False	There are no bad dogs, only bad owners.
3	dog_002	dog	white	80	2	False	Love is a wet nose and a wagging tail.
4	dog_003	dog	black	25	0.5	False	Be the person your dog thinks you are.

pets[pets[(pets.get('Weight') >= 25) &  (pets.get('Weight') < 80)]]

Index	ID	Species	Color	Weight	Age	Is_Cat	Owner_Comment
0	dog_001	dog	black	40	5	False	There are no bad dogs, only bad owners.
4	dog_003	dog	black	25	0.5	False	Be the person your dog thinks you are.

pets[pets[pets.get('Color').str.contains('e')]]

Index	ID	Species	Color	Weight	Age	Is_Cat	Owner_Comment
1	cat_001	cat	golden	1.5	0.2	True	My best birthday present ever!!!
3	dog_002	dog	white	80	2	False	Love is a wet nose and a wagging tail.
6	ham_002	hamster	golden	0.25	0.2	False	No, thank you!

pets[pets1 = pets.set_index('ID')
pets1[pets1.index.str.contains('cat')]]

Index	Species	Color	Weight	Age	Is_Cat	Owner_Comment
cat_001	cat	golden	1.5	0.2	True	My best birthday present ever!!!
cat_002	cat	black	15	9	True	****All you need is love and a cat.****
cat_003	cat	black	10	0	True	No, thank you!

pets[pets.index > 3]

Index	ID	Species	Color	Weight	Age	Is_Cat	Owner_Comment
4	dog_003	dog	black	25	0.5	False	Be the person your dog thinks you are.
5	ham_001	hamster	black	1	3	False	No, thank you!
6	ham_002	hamster	golden	0.25	0.2	False	No, thank you!
7	cat_003	cat	black	10	0	True	No, thank you!