如何使用 python 将字典保存为 PDF 中的表格，并带有单元格着色？

Question

I have a dict variable to summary the errors of my experiments, which is defined as below:

my_dict= {' ': ['A error', 'B Error', 'C Error', 'D Error'], 'lab1': [0.34, 0.23, 80, 0.79], 'lab2': [0.53, 0.38, 96, 1.25], 'lab3': [0.40, 0.27, 68, 0.93]}

Is there a way in Python to save the above dict as a table in PDF? Here, I hope to assign some thresholds to the values: if error value is larger than threshold, the cell is red, otherwise, it is green.

For example, in the above table "my_dict", I hope to set different thresholds to different cells. Could someone provide some guidance on that?

Answer 1

disclaimer: I am the author of pText

You can use pText to create the PDF you described. Let's start by creating an empty Document

    # create document
    pdf = Document()

    # add page
    page = Page()
    pdf.append_page(page)

We are going to use a layout-manager to determine where content needs to be. This is a lot easier than trying to figure out the PDF coordinate system ourselves.

    # set layout
    layout = SingleColumnLayout(page)

Next comes the fun part, actually working with your data:

    my_dict= {' ': ['A Error', 'B Error', 'C Error', 'D Error'],
              'lab1': [0.34, 0.23, 0.80, 0.79],
              'lab2': [0.53, 0.38, 0.96, 1.25],
              'lab3': [0.40, 0.27, 0.68, 0.93]}

I'm going to define a dictionary to map boundaries unto colors. You could easily change this piece of code to add more color, or change the colors.

    colors = {0: X11Color("Green"),
              0.25: X11Color("Yellow"),
              0.5: X11Color("Orange"),
              0.75: X11Color("Red")}

Next we create the Table

    table = Table(number_of_rows=4, number_of_columns=5)

Now we can call add on the table. Whenever we do, content is added at the current row (starting at the top row). If the row is full, we will automatically go to the next row.

    table.add(Paragraph(" "))

Now we add all the headers (I made them bold):

    for h in my_dict[" "]:
        table.add(Paragraph(text=h, font="Helvetica-Bold", font_size=Decimal(12)))

Next step is to actually add all your data to the Table :

    for name, row in [(k,v) for k,v in my_dict.items() if k != " "]:
        table.add(Paragraph(name))
        for v in row:
            c = X11Color("Green")
            for b,bc in colors.items():
                if v > b:
                    c = bc
            table.add(Paragraph(str(v),
                                font_color=c,
                                justification=Justification.CENTERED))

I am going to make the border on this Table a bit thinner than it would be by default:

    # set border
    table.set_border_width_on_all_cells(Decimal(0.2))

I am also going to add a Paragraph at the start of the Page to give some context as to what the table represents:

    # add to layout
    layout.add(Paragraph("This table contains all measurands for 3 lab-sessions."))

Now we add the Table to the Page

    layout.add(table)

Finally, we store the PDF:

    # attempt to store PDF
    with open("output.pdf", "wb") as in_file_handle:
        PDF.dumps(in_file_handle, pdf)

The final result looks like this (but you can play around with colors, fonts, etc)

Answer 2

You could create a pandas dataframe and then display a seaborn heatmap:

import seaborn as sns
import pandas as pd
from matplotlib import pyplot as plt

my_dict= {' ': ['A error', 'B Error', 'C Error', 'D Error'], 'lab1': [0.34, 0.23, 80, 0.79], 'lab2': [0.53, 0.38, 96, 1.25], 'lab3': [0.40, 0.27, 68, 0.93]}
df = pd.DataFrame(my_dict)
df.set_index(' ', inplace=True)
sns.heatmap(df.T, cmap='RdYlGn', annot=True, cbar_kws={'label':'Error value'})
plt.savefig('Errors.pdf')
plt.show()