Guru: Creating PDF Documents With Python

July 27, 2020 Mike Larsen

I’m often asked to create reports for my business partners. The format of the report depends on who made the request. If the financial team made the request, I may produce an Excel file. The CEO may want to report quarterly sales to their shareholders. In that case, I may produce a PDF using the company letterhead.

In a prior article, I showed how to create Excel files using Db2 tables. Now I’m going to show how to create PDF documents using Db2 tables.

This story contains code, which you can download here.

I always start by making sure all Python packages are up to date on my IBM i. I use ACS (Access Client Solutions) to update and install Python packages as shown in Figure 1.

Figure 1. Install and update Python packages (partial listing).

Next, I install the packages I’m using in my Python script. I’m using ibm_db to connect to a Db2 table and fpdf to generate the PDF. To install these packages, I execute the commands in Figure 2 using an SSH terminal like Putty or Mobaxterm.

pip3 install ibm_db
pip3 install fpdf

Figure 2. Install Python packages.

Now that all packages are installed and up to date, I’m ready to write some code!

I start by importing packages I’m using in my script (Figure 3). In addition to using ibm_db and fpdf, I’m also using the datetime module so I can print the date and time in the footer of the report.

from fpdf import FPDF
import ibm_db_dbi as db2
from datetime import datetime

Figure 3. Import packages.

I’m printing the date and time in the format of month, day, year, hour, minute, second as shown in Figure 4.

# datetime object containing current date and time
now = datetime.now()
dt_string = now.strftime("%m/%d/%Y %H:%M:%S") 

Figure 4. Format the date.

The fpdf package allows me to set up a header (Figure 5) and footer (Figure 6) for my report.  Once I define them in my script, they’re executed automatically for each new page of my report.  I’ll show each of these and explain what they’re doing.

# - - - -
# first line of the header
       
# Logo
# fpdf.image(name, x = None, y = None, w = 0, h = 0, type = '', link = '')        
  self.image('/home/MLARSEN/logo_sample.png', 10, 8, 20, 20)
        
# Arial bold 15
  self.set_font('Arial', 'B', 15)
        
# fpdf.cell(w, h = 0, txt = '', border = 0, ln = 0, 
#              align = '', fill = False, link = '')
# Title
#
# width = 40, height = 10, border = 0 (no border), 
# ln = 0 (0: to the right,
#         1: to the beginning of the next line,
#         2: below), align = Center  

self.cell(40, 10, 'Employee listing', 0, 0, 'C')
        
# - - - -
# second line of the header        
  self.set_font('Arial','U', 14.0)

  self.cell(30, 10, txt = 'First name', border = 1, ln = 0)
  self.cell(12, 10, txt = 'MI', border = 1, ln = 0)
  self.cell(30, 10, txt = 'Last name', border = 1, ln = 0)
  self.cell(30, 10, txt = 'Department', border = 1, ln = 0)
  self.cell(30, 10, txt = 'Phone no.', border = 1, ln = 0)
  self.cell(30, 10, txt = 'Job title', border = 1, ln = 0) 

Figure 5. Report header.

I have two lines in my header. On the first line, I have a logo that is pulled in from a file in the IFS.  I set the font to Arial 15 and make the text bold. Then I specify the tile of the report, Employee listing, and center it on the page.

The second line of the header contains my column headings to match the columns I’m loading from a Db2 table.  The report in this example is producing an employee listing from a sample table on my IBM i.

# 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, 'Page ' + str(self.page_no()) + '/{nb}', 0, 0, 'C')
        
# date/time
  self.cell(0, 10, dt_string, 0, 0, 'R')

Figure 6. Report footer.

For the footer, I define where on the page it should print and what font I’m using.  I also print the page number, date, and time.  The page number is printed at the center of the page and the date/time is printed at the right.

With the header and footer in place, I’m ready to start loading the report with data from the employee table.  I start by connecting to the database, then I define and execute a cursor (Figure 7).

conn = db2.connect()

cursor = conn.cursor()

cursor.execute("Select FirstNme, MidInit, LastName, WorkDept, PhoneNo, Job "
               " From Sample.Employee ")

Figure 7. Retrieve data from Employee table.

I loop through my cursor and start printing the employees to the report (Figure 8). To make this a little more interesting, I change the font color to red when an employee has a title of MANAGER and I also use a blue font color for the first employee printed. I did this for illustrative purposes to show some additional features of fpdf.

for row in cursor:
    
    # color can either be RGB as I did below, or you can use hex:
    #
    # pdf.set_text_color(*hex2dec('#8B6914'))
        
    if row[5].strip() == 'MANAGER':
        pdf.set_text_color(253, 7, 7)   # red
    elif lineNumber == 0:
        pdf.set_text_color(0, 0, 255)   # blue
    else:
        pdf.set_text_color(0, 0, 0)     # black

    pdf.cell(30, 10, txt = row[0], border = 1, ln = 0)
    pdf.cell(12, 10, txt = row[1], border = 1, ln = 0)
    pdf.cell(30, 10, txt = row[2], border = 1, ln = 0)
    pdf.cell(30, 10, txt = row[3], border = 1, ln = 0)
    pdf.cell(30, 10, txt = row[4], border = 1, ln = 0)
    pdf.cell(30, 10, txt = row[5], border = 1, ln = 0)

Figure 8. Print detail lines.

I created a summary line at the end of the report that gives a total of the number of employees printed. I also added a digital signature to the end of the report. The signature is pulled from a file in the IFS and I used the x and y coordinates to make it print on the right side of the report.

pdf.set_text_color(0, 0, 0)     # black 

pdf.cell(50, 10, txt = 'Number of Employees', border = 0, ln = 0)
pdf.cell(12, 10, txt = str(lineNumber), border = 0, ln = 0)

# create a line break.  default is 'mm' - millimeters
        
pdf.ln(10)

# get the current x and y coordinates

x = pdf.get_x() + 100       # +100 moves it over horizontally to the right
y = pdf.get_y()

# fpdf.image(name, x = None, y = None, w = 0, h = 0, type = '', link = '')

pdf.image('/home/MLARSEN/mike_larsen_signature.png', x, y, 50, 15)

Figure 9. Print summary line.

The last piece of code creates the PDF document in the IFS (Figure 10).

# 'F' = file
pdf.output("createPdf3c.pdf", 'F')

Figure 10. Create the PDF in the IFS.

I run the Python script in an SSH terminal (Figure 11) and open the PDF to review the report.  I’m only showing the first and last pages of the report (Figures 12 and 13).

python3 createPdf3c.py

Figure 11. Run the Python script.

Figure 12. First page of Employee report.

Figure 13. Last page of Employee report.

With a short Python script, I built a nice report that lives in the IFS. From here, I could email it out to whoever needs it. Hopefully, this example will get you started creating your own PDF’s using Python. The complete code for the Python script used in this article is available for download.

Mike Larsen is a Project Manager and Senior developer at Central Park Data Systems and has been working with IBM i systems for over 20 years. He specializes in RPG, CL, and SQL and recently has been working with Python. Current projects have given Mike the opportunity to generate PDFs and Excel files using Python. He has also built processes to call RPG programs from Python and execute Python scripts from RPG.

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