如何用Pandas与Matplotlib合并第三方卖家绘制卖家计数饼图？

Absolutely! You can easily achieve this using Pandas (either with a helper column or groupby) and Matplotlib. Here's how to do it step by step:

Method 1: Using a Helper Column (Simpler) #

First, create a new column that categorizes each seller into either "Amazon" or "Third-Party Sellers". Then count these categories and plot:

import pandas as pd
import numpy as np
import matplotlib.pyplot as plt

# Sample DataFrame (replace with your actual df)
data = {'seller': ['Amazon', 'SellerA', 'Amazon', 'SellerB', 'SellerC', 'Amazon']}
df = pd.DataFrame(data)

# Create a category column to group sellers
df['seller_category'] = np.where(df['seller'] == 'Amazon', 'Amazon', 'Third-Party Sellers')

# Get counts for each category
seller_counts = df['seller_category'].value_counts()

# Plot the pie chart
seller_counts.plot(kind='pie', autopct='%1.1f%%', startangle=90, colors=['#0066cc', '#ff9933'])
plt.title('Seller Distribution: Amazon vs Third-Party')
plt.ylabel('')  # Remove default y-label (unnecessary for pie charts)
plt.show()

Method 2: Using groupby (No Helper Column) #

If you prefer not to add a new column to your DataFrame, you can use groupby with a custom lambda function to directly group sellers into the two categories:

# Group sellers and calculate counts without a helper column
seller_counts = df.groupby(lambda idx: 'Amazon' if df.loc[idx, 'seller'] == 'Amazon' else 'Third-Party Sellers').size()

# Plot the pie chart (customize as needed)
seller_counts.plot(kind='pie', autopct='%1.1f%%', startangle=90)
plt.title('Seller Distribution')
plt.ylabel('')
plt.legend(loc='lower right')
plt.show()

Key Customization Tips: #

• autopct='%1.1f%%' adds percentage labels to each slice for clarity.
• startangle=90 rotates the pie chart so the first slice (Amazon) starts at the top.
• Use the colors parameter to set custom colors for each category.
• Removing the y-label (plt.ylabel('')) keeps the chart clean, as pie charts don’t require axis labels.

Both methods will produce a pie chart with exactly two slices: one for Amazon, and one for the combined total of all third-party sellers.

内容的提问来源于stack exchange，提问作者IamWarmduscher