Python使用FPDF添加JPG图片报错‘Unsupported image type’求助

我是Python初学者，正在使用FPDF库开发PDF生成程序，添加JPG图片时触发运行时错误：“FPDF error: Unsupported image type”。

完整代码 #

class PDF(FPDF):
    
    def __init__(self):
        super().__init__()
        self.header_text = ""
        self.footer_text = ""
        self.table_data = []
        self.table_header = []
        self.image_file = ""
        self.pdf_title = ""

    # Page header
    def header(self):
        if self.image_file:
            self.image(self.image_file, 80, 25, 50)
        if self.pdf_title:
            self.set_font('Arial', 'B', 15)
            self.cell(80)
            self.cell(30, 10, self.pdf_title, 0, 0, 'C')
            self.ln(50)
        if self.header_text:
            self.set_font('Arial', 'B', 12)
            self.cell(0, 10, self.header_text, 0, 0, 'C')
            self.ln(20)

    # Add a table to the PDF
    def add_table(self, header, data):
        
        # Set the font and style for the table
        self.set_font('Arial', '', 10)
        
        # Calculate the width of each column and the height of each row
        col_width = self.w * 0.9 / len(header)
        row_height = self.font_size * 1.5
        
        # Add the table header
        for col_number, column_title in enumerate(header):
            self.cell(col_width, row_height, str(column_title), border=1)
        self.ln()
        
        # Add the table data
        self.set_font('Arial', '', 10)

        for row in data:
            for item in row:
                self.cell(col_width, row_height, str(item), border=1)
            self.ln()

    # Add text to the PDF
    def add_text(self):
        self.add_page()
        # Set the font and style for the text
        self.set_font('Arial', '', 12)
        # Add the text
        self.multi_cell(0, 10, self.header_text)
        self.ln()

    # Add image to the PDF
    def add_image(self):
        self.add_page()
        # Add the image
        self.image(self.image_file, x=10, y=10, w=190)
        self.ln()

    # Page footer
    def footer(self):
        if self.footer_text:
            # Position at 1.5 cm from bottom
            self.set_y(-15)
            # Arial italic 8
            self.set_font('Arial', 'I', 8)
            # Page number
            self.cell(0, 10, self.footer_text + ' - Page ' + str(self.page_no()) + '/{nb}', 0, 0, 'C')

# Instantiation of inherited class
pdf = PDF()
# Printing lines on first page
pdf.add_page()
pdf.set_font('Times', '', 10)

# Switch statement
while True:
    print("1. Add page header")
    print("2. Add page footer")
    print("3. Add table")
    print("4. Add text")
    print("5. Add image")
    print("6. Generate PDF and exit")
    choice = int(input("Enter your choice (1-6): "))
    if choice == 1:
        pdf.header_text = input("Enter the header text: ")
        pdf.image_file = input("Enter the name of the image file (including extension): ")
        pdf.pdf_title = input("Enter the title for the PDF: ")
    elif choice == 2:
        pdf.footer_text = input("Enter the footer text: ")
        pdf.footer_page_number = input("Enter the page number for the footer: ")
    elif choice == 3:
        # Get user input for number of rows and columns
        num_cols = int(input("Enter number of columns: "))
        # Create empty header and data lists
        header = []
        data = []
        # Accept table header from user
        header_str = input("Enter table header separated by commas: ")
        header = header_str.split(",")
        # Accept table data from user
        while True:
            row_str = input("Enter table row separated by commas (enter 'done' when finished): ")
            if row_str.lower() == "done":
                break
            else:
                row = row_str.split(",")
                data.append(row)
        # Add the table to the PDF
        pdf.add_table(header, data)
    elif choice == 4:
        text = input("Enter the text: ")
        pdf.add_text()
    elif choice == 5:
        image_file = input("Enter the name of the image file (including extension): ")
        pdf.add_image()
    elif choice == 6:
        pdf.generate_pdf()
        break
    else:
        print("Invalid choice. Please enter a number between 1 and 6.")
# Creating File
pdf.output('tuto2.pdf')

错误堆栈信息 #

Enter the name of the image file (including extension): image.jpg
Traceback (most recent call last):
  File "d:\SOFTWARE\PDF in Python\pdf1.py", line 242, in <module>        
    pdf.add_image()
  File "d:\SOFTWARE\PDF in Python\pdf1.py", line 183, in add_image
  File "C:\Users\aiena\AppData\Local\Programs\Python\Python311\Lib\site-packages\fpdf\fpdf.py", line 150, in wrapper
    return fn(self, *args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\aiena\AppData\Local\Programs\Python\Python311\Lib\site-packages\fpdf\fpdf.py", line 990, in image
    self.error('Unsupported image type: '+type)
  File "C:\Users\aiena\AppData\Local\Programs\Python\Python311\Lib\site-packages\fpdf\fpdf.py", line 227, in error
    raise RuntimeError('FPDF error: '+msg)
RuntimeError: FPDF error: Unsupported image type:

错误原因 #

核心问题是选项5的代码未将用户输入的图片路径赋值给PDF实例的image_file属性：

• 当选择选项5时，代码仅获取了用户输入的image_file变量，但没有赋值给pdf.image_file
• 调用pdf.add_image()时，self.image_file是空字符串，FPDF无法识别空路径的图片类型，因此抛出错误

此外还有两处潜在问题：

1. add_image()方法未对self.image_file做非空校验，直接调用image()方法会报错
2. 未校验图片文件是否存在，若用户输入错误路径也会触发异常

修复方案 #

1. 修复选项5的赋值逻辑 #

修改选项5的代码，将用户输入的图片路径赋值给pdf.image_file：

elif choice == 5:
    pdf.image_file = input("Enter the name of the image file (including extension): ")
    pdf.add_image()

2. 给add_image()方法添加非空与文件存在校验 #

增强鲁棒性，避免无效调用：

import os

# Add image to the PDF
def add_image(self):
    if not self.image_file:
        print("Error: No image file specified")
        return
    if not os.path.exists(self.image_file):
        print(f"Error: Image file '{self.image_file}' does not exist")
        return
    self.add_page()
    # Add the image
    self.image(self.image_file, x=10, y=10, w=190)
    self.ln()

3. 修复其他无效逻辑 #

• 移除选项6中不存在的generate_pdf()调用，直接使用pdf.output()
• 修复选项4中未将用户输入文本赋值给pdf.header_text的问题
• 移除选项2中未使用的footer_page_number输入逻辑

最终修复后的完整代码 #

import os
from fpdf import FPDF

class PDF(FPDF):
    
    def __init__(self):
        super().__init__()
        self.header_text = ""
        self.footer_text = ""
        self.table_data = []
        self.table_header = []
        self.image_file = ""
        self.pdf_title = ""

    # Page header
    def header(self):
        if self.image_file:
            self.image(self.image_file, 80, 25, 50)
        if self.pdf_title:
            self.set_font('Arial', 'B', 15)
            self.cell(80)
            self.cell(30, 10, self.pdf_title, 0, 0, 'C')
            self.ln(50)
        if self.header_text:
            self.set_font('Arial', 'B', 12)
            self.cell(0, 10, self.header_text, 0, 0, 'C')
            self.ln(20)

    # Add a table to the PDF
    def add_table(self, header, data):
        
        # Set the font and style for the table
        self.set_font('Arial', '', 10)
        
        # Calculate the width of each column and the height of each row
        col_width = self.w * 0.9 / len(header)
        row_height = self.font_size * 1.5
        
        # Add the table header
        for col_number, column_title in enumerate(header):
            self.cell(col_width, row_height, str(column_title), border=1)
        self.ln()
        
        # Add the table data
        self.set_font('Arial', '', 10)

        for row in data:
            for item in row:
                self.cell(col_width, row_height, str(item), border=1)
            self.ln()

    # Add text to the PDF
    def add_text(self):
        self.add_page()
        # Set the font and style for the text
        self.set_font('Arial', '', 12)
        # Add the text
        self.multi_cell(0, 10, self.header_text)
        self.ln()

    # Add image to the PDF
    def add_image(self):
        if not self.image_file:
            print("Error: No image file specified")
            return
        if not os.path.exists(self.image_file):
            print(f"Error: Image file '{self.image_file}' does not exist")
            return
        self.add_page()
        # Add the image
        self.image(self.image_file, x=10, y=10, w=190)
        self.ln()

    # Page footer
    def footer(self):
        if self.footer_text:
            # Position at 1.5 cm from bottom
            self.set_y(-15)
            # Arial italic 8
            self.set_font('Arial', 'I', 8)
            # Page number
            self.cell(0, 10, self.footer_text + ' - Page ' + str(self.page_no()) + '/{nb}', 0, 0, 'C')

# Instantiation of inherited class
pdf = PDF()
# Printing lines on first page
pdf.add_page()
pdf.set_font('Times', '', 10)

# Switch statement
while True:
    print("1. Add page header")
    print("2. Add page footer")
    print("3. Add table")
    print("4. Add text")
    print("5. Add image")
    print("6. Generate PDF and exit")
    choice = int(input("Enter your choice (1-6): "))
    if choice == 1:
        pdf.header_text = input("Enter the header text: ")
        pdf.image_file = input("Enter the name of the image file (including extension): ")
        pdf.pdf_title = input("Enter the title for the PDF: ")
    elif choice == 2:
        pdf.footer_text = input("Enter the footer text: ")
    elif choice == 3:
        # Get user input for number of rows and columns
        num_cols = int(input("Enter number of columns: "))
        # Create empty header and data lists
        header = []
        data = []
        # Accept table header from user
        header_str = input("Enter table header separated by commas: ")
        header = header_str.split(",")
        # Accept table data from user
        while True:
            row_str = input("Enter table row separated by commas (enter 'done' when finished): ")
            if row_str.lower() == "done":
                break
            else:
                row = row_str.split(",")
                data.append(row)
        # Add the table to the PDF
        pdf.add_table(header, data)
    elif choice == 4:
        pdf.header_text = input("Enter the text: ")
        pdf.add_text()
    elif choice == 5:
        pdf.image_file = input("Enter the name of the image file (including extension): ")
        pdf.add_image()
    elif choice == 6:
        pdf.output('tuto2.pdf')
        print("PDF generated successfully!")
        break
    else:
        print("Invalid choice. Please enter a number between 1 and 6.")

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