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Pandas is a popular Python library used for data analysis and manipulation. It provides various methods for accessing and manipulating data within a DataFrame, including the ability to retrieve the index of a specific column using its name. This can be achieved by using the “get_loc” method, which takes the column name as input and returns its corresponding index. This functionality is useful for identifying and selecting specific columns within a DataFrame for further analysis or manipulation. Overall, Pandas provides a convenient and efficient way to retrieve column indices, making it a valuable tool for data analysis tasks.
Pandas: Get Column Index from Column Name
You can use the following methods to get the column index value from a column name in pandas:
Method 1: Get Column Index for One Column Name
df.columns.get_loc('this_column')
Method 2: Get Column Index for Multiple Column Names
cols = ['this_column', 'that_column'] [df.columns.get_loc(c) for c in cols if c in df]
The following examples show how to use each method in practice with the following pandas DataFrame:
import pandas as pd #create DataFrame df = pd.DataFrame({'store': ['A', 'A', 'A', 'A', 'B', 'B', 'B', 'B'], 'sales': [18, 10, 14, 13, 19, 24, 25, 29], 'returns': [1, 2, 2, 3, 2, 3, 5, 4], 'recalls': [0, 0, 2, 1, 1, 2, 0, 1]}) #view DataFrame print(df) store sales returns recalls 0 A 18 1 0 1 A 10 2 0 2 A 14 2 2 3 A 13 3 1 4 B 19 2 1 5 B 24 3 2 6 B 25 5 0 7 B 29 4 1
Example 1: Get Column Index for One Column Name
The following code shows how to get the column index value for the column with the name ‘returns’:
#get column index for column with the name 'returns' df.columns.get_loc('returns') 2
The column with the name ‘returns’ has a column index value of 2.
Note: Column index values start at 0 in Python. Thus, since ‘returns’ is the third column in the DataFrame, it has an index value of 2.
Example 2: Get Column Index for Multiple Column Names
The following code shows how to get the column index value for several columns in the DataFrame:
#define list of columns to get index for cols = ['store', 'returns', 'recalls'] #get column index for each column in list [df.columns.get_loc(c) for c in cols if c in df] [0, 2, 3]
From the output we can see:
- The column with the name ‘store’ has a column index value of 0.
- The column with the name ‘returns’ has a column index value of 2.
- The column with the name ‘recalls’ has a column index value of 3.
The following tutorials explain how to perform other common tasks in pandas:
Cite this article
stats writer (2024). How can I get the column index from a specific column name using Pandas?. PSYCHOLOGICAL SCALES. Retrieved from https://scales.arabpsychology.com/stats/how-can-i-get-the-column-index-from-a-specific-column-name-using-pandas/
stats writer. "How can I get the column index from a specific column name using Pandas?." PSYCHOLOGICAL SCALES, 27 Jun. 2024, https://scales.arabpsychology.com/stats/how-can-i-get-the-column-index-from-a-specific-column-name-using-pandas/.
stats writer. "How can I get the column index from a specific column name using Pandas?." PSYCHOLOGICAL SCALES, 2024. https://scales.arabpsychology.com/stats/how-can-i-get-the-column-index-from-a-specific-column-name-using-pandas/.
stats writer (2024) 'How can I get the column index from a specific column name using Pandas?', PSYCHOLOGICAL SCALES. Available at: https://scales.arabpsychology.com/stats/how-can-i-get-the-column-index-from-a-specific-column-name-using-pandas/.
[1] stats writer, "How can I get the column index from a specific column name using Pandas?," PSYCHOLOGICAL SCALES, vol. X, no. Y, ص Z-Z, June, 2024.
stats writer. How can I get the column index from a specific column name using Pandas?. PSYCHOLOGICAL SCALES. 2024;vol(issue):pages.
