在一個 pdf 文件中添加兩個圖形

Question

如何在一個pdf文件中添加兩個數字（一個bar chart和一個table ）？ 我現在正在做的是：

from plotly import graph_objs as go
import numpy as np
import os
from IPython.display import Image

# Chart product views
fig = go.Figure(
    data = [go.Bar(
        x=[
            "01/09/2019 - 07/09/2019",
            "08/09/2019 - 14/09/2019", 
            "15/09/2019 - 21/09/2019",
            "22/09/2019 - 28/09/2019"
            ],
        y=[15, 25, 35, 32]
        ),
    ],
    layout=dict(
        yaxis=dict(
            title="Product views"
        ),
        autosize=False,
        width=1000,
        height=600,
    ),
)

# Table product views
fig2 = go.Figure(
    data=[
        go.Table(
            header=dict(values=["Period", "Views"]),
            cells=dict(values=[
                [
                    "01/09/2019 - 07/09/2019",
                    "08/09/2019 - 14/09/2019", 
                    "15/09/2019 - 21/09/2019",
                    "22/09/2019 - 28/09/2019"
                ],
                [15, 25, 35, 32]
            ])
        )
    ],
    layout=dict(
        autosize=False,
        width=800,
        height=300,
        title=dict(
            text="<b>Library Shelving</b> statistic"
        )
    )
)

if not os.path.exists("images"):
    os.mkdir("images")

fig.write_image("images/fig1.pdf")
fig2.write_image("images/fig2.pdf")

成功創建 2 個 pdf。 有沒有辦法做到這一點？

Answer 1

使用PdfPages解決您的問題。 我寫了這個小代碼作為一個例子：

import matplotlib.backends.backend_pdf
import matplotlib.pyplot as plt
import numpy as np

pdf = matplotlib.backends.backend_pdf.PdfPages("output.pdf")

fig1 = plt.figure()
ax1 = fig1.add_subplot(111)
ax1.plot([1, 2, 3], [1, 2, 3])

fig2 = plt.figure()
ax2 = fig2.add_subplot(111)
x = np.linspace(1, 20)
ax2.plot(x, x * x)

for fig in [fig1, fig2]:
    pdf.savefig(fig)
pdf.close()

希望這可以幫助。

Answer 2

我已經能夠使用以下方法完成此操作：

• plotly.io.to_image()將數字寫入圖像字節數據
• PIL.Image.open()讀取字節數據
• PIL.Image.convert()將字節數據轉換為 RGB
• io.BytesIO()臨時存儲轉換后的圖像數據
• PIL.Image.save()將第一個圖像保存到 PDF 和 append 圖中的所有其他 PDF 到第一個圖像

結果將是圖像的多頁 PDF。

您可能需要pip install pillow

import plotly.io as pio
import io
from PIL import Image

figures = [fig1, fig2, fig3]
image_list = [pio.to_image(fig, format='png', width=1440, height=900, scale=1.5) for fig in figures]
for index, image in enumerate(image_list):
    with io.BytesIO() as tmp:
        tmp.write(image)  # write the image bytes to the io.BytesIO() temporary object
        image = Image.open(tmp).convert('RGB')  # convert and overwrite 'image' to prevent creating a new variable
        image_list[index] = image  # overwrite byte image data in list, replace with PIL converted image data

# pop first item from image_list, use that to access .save(). Then refer back to image_list to append the rest
image_list.pop(0).save(r'/Users/USERNAME/plotly_dash.pdf', 'PDF',
                       save_all=True, append_images=image_list, resolution=100.0)  # TODO improve resolution