Preparation
Before any data manipulation can occur, two (2) new libraries will require installation.
- The Pandas library enables access to/from a DataFrame.
- The NumPy library supports multi-dimensional arrays and matrices in addition to a collection of mathematical functions.
To install these libraries, navigate to an IDE terminal. At the command prompt ($
), execute the code below. For the terminal used in this example, the command prompt is a dollar sign ($
). Your terminal prompt may be different.
$ pip install pandas
Hit the <Enter>
key on the keyboard to start the installation process.
$ pip install numpy
Hit the <Enter>
key on the keyboard to start the installation process.
If the installations were successful, a message displays in the terminal indicating the same.
Feel free to view the PyCharm installation guide for the required libraries.
Add the following code to the top of each code snippet. This snippet will allow the code in this article to run error-free.
import pandas as pd import numpy as np
DataFrame min()
The min()
method returns the smallest value(s) from a DataFrame/Series. The following methods can accomplish this task:
- The
DataFrame.min()
method, or - The
numpy.minimum()
method
The syntax for this method is as follows:
DataFrame.min(axis=None, skipna=None, level=None, numeric_only=None, **kwargs)
Parameter | Description |
---|---|
axis | If zero (0) or index is selected, apply to each column. Default 0. If one (1) apply to each row. |
skipna | If this parameter is True , any NaN /NULL value(s) ignored. If False , all value(s) included: valid or empty. If no value, then None is assumed. |
level | Set the appropriate parameter if the DataFrame/Series is multi-level. If no value, then None is assumed. |
numeric_only | Only include columns that contain integers, floats, or boolean values. |
**kwargs | This is where you can add additional keywords. |
For this example, we will determine which Team(s) have the smallest amounts of wins, losses, or ties.
Code Example 1
df_teams = pd.DataFrame({'Bruins': [4, 5, 9], 'Oilers': [3, 6, 14], 'Leafs': [2, 7, 11], 'Flames': [21, 8, 7]}) result = df_teams.min(axis=0) print(result)
- Line [1] creates a DataFrame from a dictionary of lists and saves it to
df_teams
. - Line [2] uses the
min()
method with the axis parameter set to columns to retrieve the minimum value(s) from the DataFrame. This output saves to theresult
variable. - Line [3] outputs the result to the terminal.
Output
Bruins | 4 |
Oilers | 3 |
Leafs | 2 |
Flames | 8 |
dtype: | int64 |
This example uses two (2) arrays and retrieves the Series’s minimum value(s).
Code Example 2
c11_grades = [63, 78, 83, 93] c12_grades = [73, 84, 79, 83] result = np.minimum(c11_grades, c12_grades) print(result)
- Line [1-2] creates lists of random grades and assigns them to the appropriate variable.
- Line [3] uses NumPy minimum to compare the two (2) arrays. This output saves to the
result
variable. - Line [4] outputs the result to the terminal.
Output
[63 78 79 83]
More Pandas DataFrame Methods
Feel free to learn more about the previous and next pandas DataFrame methods (alphabetically) here:
Also, check out the full cheat sheet overview of all Pandas DataFrame methods.