You can use the following methods to get frequency counts of values in a column of a pandas DataFrame:
Method 1: Get Frequency Count of Values in Table Format
df['my_column'].value_counts()
Method 2: Get Frequency Count of Values in Dictionary Format
df['my_column'].value_counts().to_dict()
The following examples shows how to use each method in practice with the following pandas DataFrame:
import pandas as pd #create DataFrame df = pd.DataFrame({'team': ['A', 'A', 'A', 'A', 'B', 'B', 'B', 'C'], 'points': [12, 20, 25, 8, 12, 19, 27, 35]}) #view DataFrame print(df) team points 0 A 12 1 A 20 2 A 25 3 A 8 4 B 12 5 B 19 6 B 27 7 C 35
Example 1: Get Frequency Count of Values in Table Format
We can use the value_counts() function to get a frequency count of each unique value in the team column of the DataFrame and display the results in a table format:
#get frequency count of values in 'team' column df['team'].value_counts() A 4 B 3 C 1 Name: team, dtype: int64
From the results we can see:
- The value ‘A’ occurs 4 times in the team column.
- The value ‘B’ occurs 3 times in the team column.
- The value ‘C’ occurs 1 time in the team column.
Notice that the results are displayed in a table format.
Example 2: Get Frequency Count of Values in Dictionary Format
We can use the value_counts() function and the to_dict() function to get a frequency count of each unique value in the team column of the DataFrame and display the results in a dictionary format:
#get frequency count of values in 'team' column and display in dictionary df['team'].value_counts().to_dict() {'A': 4, 'B': 3, 'C': 1}
The frequency counts of each unique value in the team column are shown in a dictionary format.
For example, we can see:
- The value ‘A’ occurs 4 times in the team column.
- The value ‘B’ occurs 3 times in the team column.
- The value ‘C’ occurs 1 time in the team column.
This matches the frequency counts in the previous method.
The results are simply shown in a different format.
Additional Resources
The following tutorials explain how to perform other common tasks in pandas:
Pandas: How to Use GroupBy and Value Counts
Pandas: How to Use GroupBy with Bin Counts
Pandas: How to Count Values in Column with Condition