Python多图表合并PDF页面问题：将4张图表合并为2页

Got it, let's get this sorted! The issue right now is that you're creating a separate figure for each individual chart, and each pdf.savefig() call adds a new page. To put two charts per page (one company's financials + stock price), we'll use matplotlib's subplot system to stack both charts onto a single figure, then save that figure once per company.

Here's the revised code with explanations:

import matplotlib.pyplot as plt
from matplotlib.dates import DateFormatter
import numpy as np
from matplotlib.backends.backend_pdf import PdfPages

with PdfPages('multipage_pdf.pdf') as pdf:
    # ---------------------- FIRST COMPANY: Page 1 ----------------------
    # Create a single figure with 2 rows, 1 column of subplots
    fig, (ax1, ax2) = plt.subplots(2, 1, figsize=(8, 10))  # Adjust figsize as needed

    # --- Top subplot: Financial bar chart ---
    index = np.arange(n_groups)
    bar_width = 0.35
    opacity = 0.8
    rects1 = ax1.bar(index, z, bar_width, alpha=opacity, color='b', label='Zysk_(strata)_netto')
    rects2 = ax1.bar(index + bar_width, v, bar_width, alpha=opacity, color='g', label='Zysk_(strata)_działal_oper')
    rects3 = ax1.bar(index + bar_width*2, b, bar_width, alpha=opacity, color='y', label='EBITDA')
    ax1.set_xlabel('Kwartaly')
    ax1.set_ylabel('PLN')
    ax1.set_title(companys_to_chart[0])
    ax1.set_xticks(index + bar_width, x)
    ax1.legend()
    ax1.grid(True)

    # --- Bottom subplot: Stock price + WIG chart ---
    x_stock = company['Date']
    y_stock = company['Close']
    x_wig = WIG['Date']
    y_wig = WIG['Close']
    
    ax2.plot(x_stock, y_stock, label='Price')
    ax2.set_ylabel("PLN")
    ax2.set_xlabel("Date")
    ax2.grid(True)
    
    # Twin axis for WIG
    ax2_twin = ax2.twinx()
    ax2_twin.plot(x_wig, y_wig, 'y-', label='WIG')
    ax2_twin.set_ylabel('Points', size=10)
    
    # Format dates
    myFmt = DateFormatter("%d-%m-%y")
    ax2.xaxis.set_major_formatter(myFmt)
    fig.autofmt_xdate()
    
    # Combine legends for the bottom chart
    lines1, labels1 = ax2.get_legend_handles_labels()
    lines2, labels2 = ax2_twin.get_legend_handles_labels()
    ax2.legend(lines1 + lines2, labels1 + labels2, bbox_to_anchor=(0.85, 0.35))
    ax2.set_title(name_of_company)

    # Adjust layout to prevent overlapping
    plt.tight_layout()
    # Save the entire figure (both charts) as one page
    pdf.savefig(fig)
    plt.close()

    # ---------------------- SECOND COMPANY: Page 2 ----------------------
    # Repeat the same structure for the second company
    fig, (ax1, ax2) = plt.subplots(2, 1, figsize=(8, 10))

    # --- Top subplot: Financial bar chart ---
    index = np.arange(n_groups)
    bar_width = 0.35
    opacity = 0.8
    rects1 = ax1.bar(index, z_1, bar_width, alpha=opacity, color='b', label='Zysk_(strata)_netto')
    rects2 = ax1.bar(index + bar_width, v_1, bar_width, alpha=opacity, color='g', label='Zysk_(strata)_działal_oper')
    rects3 = ax1.bar(index + bar_width*2, b_1, bar_width, alpha=opacity, color='y', label='EBITDA')
    ax1.set_xlabel('Kwartaly')
    ax1.set_ylabel('PLN')
    ax1.set_title(companys_to_chart[1])
    ax1.set_xticks(index + bar_width, x_1)  # Fixed: use x_1 instead of x here
    ax1.legend()
    ax1.grid(True)

    # --- Bottom subplot: Stock price + WIG chart ---
    x_stock = company_2['Date']  # Fixed: use company_2's data here (original code used company)
    y_stock = company_2['Close']
    x_wig = WIG['Date']
    y_wig = WIG['Close']
    
    ax2.plot(x_stock, y_stock, label='Price')
    ax2.set_ylabel("PLN")
    ax2.set_xlabel("Date")
    ax2.grid(True)
    
    ax2_twin = ax2.twinx()
    ax2_twin.plot(x_wig, y_wig, 'y-', label='WIG')
    ax2_twin.set_ylabel('Points', size=10)
    
    myFmt = DateFormatter("%d-%m-%y")
    ax2.xaxis.set_major_formatter(myFmt)
    fig.autofmt_xdate()
    
    lines1, labels1 = ax2.get_legend_handles_labels()
    lines2, labels2 = ax2_twin.get_legend_handles_labels()
    ax2.legend(lines1 + lines2, labels1 + labels2, bbox_to_anchor=(0.85, 0.35))
    ax2.set_title(name_of_company_1)

    plt.tight_layout()
    pdf.savefig(fig)
    plt.close()

Key Changes Made: #

• Single figure per company: We use plt.subplots(2, 1) to create a figure with two stacked subplots (top = financial chart, bottom = stock chart).
• Fixed minor bugs: Corrected references to company_2 data in the second company's stock chart, and used x_1 for the second company's quarter labels.
• Improved legend handling: Combined legends for the twin-axis stock/WIG chart to avoid overlapping issues.
• Layout adjustment: plt.tight_layout() ensures all labels and titles fit without overlapping.

Now your PDF will have exactly 2 pages—each page containing both charts for one company!

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