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[895] Sort the rows of a DataFrame

发布时间 2023-10-10 08:40:51作者: McDelfino

In Pandas, the sort_values() method is used to sort the rows of a DataFrame by one or more columns. This method allows you to specify which column(s) to use for sorting and the sort order (ascending or descending). Here's how to use sort_values():

import pandas as pd

# Create a sample DataFrame
data = {'Name': ['Alice', 'Bob', 'Charlie', 'David', 'Eve'],
        'Age': [25, 32, 18, 47, 22],
        'Salary': [50000, 60000, 45000, 75000, 42000]}

df = pd.DataFrame(data)

# Sort the DataFrame by a single column (e.g., 'Age') in ascending order
sorted_df = df.sort_values(by='Age')

# To sort in descending order, use the 'ascending' parameter
sorted_df_desc = df.sort_values(by='Age', ascending=False)

# To sort by multiple columns, pass a list of column names
sorted_multi = df.sort_values(by=['Age', 'Salary'])

# Display the sorted DataFrames
print("Sorted by Age (ascending):")
print(sorted_df)

print("\nSorted by Age (descending):")
print(sorted_df_desc)

print("\nSorted by Age and Salary (both ascending):")
print(sorted_multi)

In this example:

  • We create a sample DataFrame df with columns 'Name', 'Age', and 'Salary'.
  • We use sort_values() to sort the DataFrame based on the 'Age' column. By default, it sorts in ascending order.
  • To sort in descending order, we pass the ascending=False parameter.
  • To sort by multiple columns, we pass a list of column names to the by parameter.

Here are the sorted DataFrames:

Sorted by Age (ascending):

      Name  Age  Salary
2  Charlie   18   45000
0    Alice   25   50000
4      Eve   22   42000
1      Bob   32   60000
3    David   47   75000

Sorted by Age (descending):

      Name  Age  Salary
3    David   47   75000
1      Bob   32   60000
0    Alice   25   50000
4      Eve   22   42000
2  Charlie   18   45000

Sorted by Age and Salary (both ascending):

      Name  Age  Salary
2  Charlie   18   45000
4      Eve   22   42000
0    Alice   25   50000
1      Bob   32   60000
3    David   47   75000

You can adjust the sorting behavior by specifying the columns and sort order according to your needs.