Packages

Intermediate Python for Developers

George Boorman

Curriculum Manager, DataCamp

Modules are Python files

Module = Python file
Anyone can create a Python file!

Code file on a laptop

¹ Image source: https://unsplash.com/@jstrippa

Packages

A collection of modules = Package
- Might also hear it called a library
Packages are publicly available and free
First need to be downloaded from PyPI
Then can be imported and used like modules

Large cardboard box

¹ https://pypi.org/

Installing a package

Terminal / Command Prompt
- Allows us to run commands to perform tasks

python3 -m pip install <package_name>

python3 - Used to execute Python code from the terminal
pip - Preferred Installer Program

Installing a package

python3 -m pip install pandas

Pandas logo.png

Importing with an alias

# Import pandas
import pandas

Need to write pandas before every function

# Import pandas using an alias
import pandas as pd

Creating a DataFrame

# Sales dictionary
sales = {"user_id": ["KM37", "PR19", "YU88"],
         "order_value": [197.75, 208.21, 134.99]}


# Convert to a pandas DataFrame
sales_df = pd.DataFrame(sales)


sales_df

  user_id  order_value
0    KM37       197.75
1    PR19       208.21
2    YU88       134.99

Reading in a CSV file

# Reading in a CSV file in our current directory
sales_df = pd.read_csv("sales.csv")


# Checking the data type
type(sales_df)

pandas.core.frame.DataFrame

Previewing the file

# DataFrame method to preview the first five rows
sales_df.head()

  user_id  order_value
0    KM37       197.75
1    PR19       208.21
2    YU88       134.99
3    NT43       153.54        
4    IW06       379.47

See DataCamp for pandas courses!

Functions versus methods

Function = code to perform a task
Method = a function that is specific to a data type

Functions versus methods

# This is a built-in function
sum([1, 2 ,3, 4, 5])

# This is a pandas function
sales_df = pd.DataFrame(sales)

.head() won't work with other data types:
- e.g., lists, dictionaries

# This is a method
# It is specific to a DataFrame data type
sales_df.head()

  user_id  order_value
0    KM37       197.75
1    PR19       208.21
2    YU88       134.99
3    NT43       153.54        
4    IW06       379.47

Let's practice!

Intermediate Python for Developers