python：使用reporttable进行pdf换行 - 错误：“float”对象不支持项目分配

Question

我正在尝试在（横向布局）pdf 上用 python 打印包含许多列（至少 6 列）的表格并包装列。 在这个generate_pdf2中，我遇到了编译错误，我自己无法成功解决:( 感谢您的帮助！

def generate_pdf2(df_list, titles, calculated_prices):
# Create a landscape layout PDF
doc = SimpleDocTemplate("pricing_information.pdf", pagesize=landscape(A4))

# Initialize a list to hold the elements of the PDF
elements = []

# Define styles for the paragraphs
styles = getSampleStyleSheet()
normal_style = styles["Normal"]

# Add title and information depending on variables
for title, calculated_price in zip(titles, calculated_prices):
    elements.append(Paragraph(title, normal_style))
    elements.append(Paragraph(f"Calculated Price: {calculated_price}", normal_style))
    elements.append(Paragraph("", normal_style))  # Add empty line for spacing

# Add tables with DataFrame titles and calculated prices
for df, title, calculated_price in zip(df_list, titles, calculated_prices):
    # Convert DataFrame to a list of lists for the table
    data = [list(df.columns)] + df.astype(str).values.tolist()
    
    # Adjust column widths to fit content within the page
    # col_widths = [len(str(df[col].max())) * 12 for col in df.columns]
    # col_widths = [float(width) for width in col_widths]  # Convert to float
    col_widths = [(float(len(str(df[col].max()))) * 12.0) for col in df.columns]

    # Create a Table object with wrapped text
    table = Table(data, colWidths=col_widths)
    
    # Apply styles to the table
    table.setStyle(TableStyle([('BACKGROUND', (0, 0), (-1, 0), 'lightgrey'),
                               ('TEXTCOLOR', (0, 0), (-1, 0), 'black'),
                               ('ALIGN', (0, 0), (-1, -1), 'CENTER'),
                               ('FONTNAME', (0, 0), (-1, 0), 'Helvetica-Bold'),
                               ('BOTTOMPADDING', (0, 0), (-1, 0), 12),
                               ('BACKGROUND', (0, 1), (-1, -1), 'white'),
                               ('GRID', (0, 0), (-1, -1), 1, 'black')]))
    
    # Wrap text in cells
    width, height = A4
    for i in range(len(data)):
        for j in range(len(data[i])):
            table._argW[i][j] = col_widths[j]  # Set cell widths
            table._argH[j] = 20  # Set cell height for wrapping text
    
    # Add table to the elements list
    elements.append(Paragraph(title, normal_style))
    elements.append(table)
    elements.append(Paragraph("", normal_style))  # Add empty line for spacing

# Build the PDF document
doc.build(elements)

# Example usage:
# Create example DataFrames, titles, and calculated prices
df1 = pd.DataFrame({'A': [1, 2, 3], 'B': [4, 5, 6]})
df2 = pd.DataFrame({'X': [7, 8, 9], 'Y': [10, 11, 12]})
df3 = pd.DataFrame({'M': [13, 14, 15], 'N': [16, 17, 18]})
df_list = [df1, df2, df3]
titles = ['DataFrame 1', 'DataFrame 2', 'DataFrame 3']
calculated_prices = [100, 200, 300]  # Example calculated prices

# Generate PDF
generate_pdf2(df_list, titles, calculated_prices)

我收到以下错误：

    <ipython-input-13-20731d70741e> in generate_pdf2(df_list, titles, calculated_prices)
    105         for i in range(len(data)):
    106             for j in range(len(data[i])):
--> 107                 table._argW[i][j] = col_widths[j]  # Set cell widths
    108                 table._argH[j] = 20  # Set cell height for wrapping text
    109 

TypeError: 'float' object does not support item assignment

也许这很简单，但我很挣扎。也许另一双眼睛可能会有所帮助。

Answer 1

您正在尝试为浮点对象赋值：

table._argW[i][j] = col_widths[j]

。

table._argW[i]

是一个浮点数，而不是一个列表，在 Python 中你不能这样做。

这是更正后的代码：

width, height = A4
for i in range(len(data[0])):
    table._argW[i] = col_widths[i]
for i in range(len(data)):
    table._argH[i] = 20