100% satisfaction guarantee Immediately available after payment Both online and in PDF No strings attached
logo-home
Summary Python Data Operations 3: Filtering $7.60   Add to cart

Summary

Summary Python Data Operations 3: Filtering

 8 views  0 purchase
  • Course
  • Institution
  • Book

Notes of Pandas data operations covered in the Principles of Programming course, part of the Computer Science and AI bachelor degree. The notes are initially written in Jupyter Notebook. They contain practical examples of data operations in python and images to explain the structures and processes....

[Show more]

Preview 2 out of 10  pages

  • No
  • Pandas data wrangling
  • December 9, 2022
  • 10
  • 2022/2023
  • Summary
avatar-seller
Python Data Operations 3: Filtering
(Using the numpy and pandas packages imported in section one.)

This third section contains:

Conditional Selection
pd.Series and Operators
Basic Filters
Missing Values

Identify Nulls
Filter Nulls
Fill in Nulls
Remove Nulls
Unique Values
# create test dataframe
test_df = pd.DataFrame([
['A3', 0, -1, 0, 'si'],
['B1', 1, None, 0, 'no'],
['B3', 4, None, 0, 'no'],
['B3', 5, 1, 0, 'si'],
['A1', 4, 0, None, None],
['A3', 1, 2, 1, 'si'],
['C2', 4, 1, 1, 'no']],
columns=['A', 'B', 'C', 'D', 'E'],
index=[f'R{i}' for i in range(7)]
)
test_df


A B C D E

R0 A3 0 -1.0 0.0 si

R1 B1 1 NaN 0.0 no

R2 B3 4 NaN 0.0 no

R3 B3 5 1.0 0.0 si

R4 A1 4 0.0 NaN None

R5 A3 1 2.0 1.0 si

R6 C2 4 1.0 1.0 no




Conditional selection
In pandas conditional selection is filtering some records according to certain criteria

, The syntax is df[filter] where filter is a sequence of boolean values of the same length
as the table, and the command allows us to select/filter records according to a certain
condition.



# create simple filter
filter = [True, True, False, False, True, True, False]
filter

[True, True, False, False, True, True, False]


# apply simple filter
# .iloc and .loc are equivalent here
test_df.iloc[filter, :]
test_df.loc[filter, :]


A B C D E

R0 A3 0 -1.0 0.0 si

R1 B1 1 NaN 0.0 no

R4 A1 4 0.0 NaN None

R5 A3 1 2.0 1.0 si



# filter columns containing a list of column names
columns = ['A', 'B', 'C']
# apply columns filter
test_df.loc[:, columns]
test_df[columns] #equivalent to previous line

The benefits of buying summaries with Stuvia:

Guaranteed quality through customer reviews

Guaranteed quality through customer reviews

Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.

Quick and easy check-out

Quick and easy check-out

You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.

Focus on what matters

Focus on what matters

Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!

Frequently asked questions

What do I get when I buy this document?

You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.

Satisfaction guarantee: how does it work?

Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.

Who am I buying these notes from?

Stuvia is a marketplace, so you are not buying this document from us, but from seller beatricemossberg. Stuvia facilitates payment to the seller.

Will I be stuck with a subscription?

No, you only buy these notes for $7.60. You're not tied to anything after your purchase.

Can Stuvia be trusted?

4.6 stars on Google & Trustpilot (+1000 reviews)

78252 documents were sold in the last 30 days

Founded in 2010, the go-to place to buy study notes for 14 years now

Start selling
$7.60
  • (0)
  Add to cart