I am writing a python CGI script that parses a csv file line by line and creates a HTML table using jinja2. Ideally, each individual HTML instance (one for each line) will get saved as a PDF report.
I've done a lot of searching, and I haven't been able to find a good way to go from HTML to PDF using python. Is it possible to render CGI to PDF? What methods would you recommend to accomplish this task?
If you've done a lot of searching then I am sure you have seen all of the really complicated options for converting html to pdf: ReportLab, weasyprint, pdfkit, etc: as catalogued in this post: How to convert webpage into pdf using Python.
However, I literally just spent the last month working on the Jinja2 -> HTML -> PDF workflow, so hopefully something of my solution can help you. I found downloading wkhtmltopdf (a small command line program written in C - it's pretty great) and using it from subprocess be by far the easiest way to accomplish this task. My sample below:
import os
import jinja2
import subprocess
def render(template_path, context):
# Context = jinja context dictionary
path, filename = os.path.split(template_path)
return jinja2.Environment(loader=jinja2.FileSystemLoader(path or './')
).get_template(filename
).render(context)
def create_pdf(custom_data, template_path, out_dir, context, keep_html=False):
# Custom data = the part of my workflow that won't matter to you
report_name = os.path.join(out_dir, custom_data + "_report")
html_name = report_name + ".html"
pdf_name = report_name + ".pdf"
def write_html():
with open(html_name, 'w') as f:
html = render(template_path, context)
f.write(html)
write_html()
args = '"C:\\Program Files\\wkhtmltopdf\\bin\\wkhtmltopdf.exe" --zoom 0.75 -B 0 -L 0 -R 0 -T 0 {} {}'.format(html_name, pdf_name)
child = subprocess.Popen(args, shell=True, stdout=subprocess.PIPE)
# Wait for the sub-process to terminate (communicate) then find out the
# status code
output, errors = child.communicate()
if child.returncode or errors:
# Change this to a log message
print "ERROR: PDF conversion failed. Subprocess exit status {}".format(
child.returncode)
if not keep_html:
# Try block only to avoid raising an error if you've already moved
# or deleted the html
try:
os.remove(html_name)
except OSError:
pass
Most of this code is well-explained by the documentation for jinja2 and subprocess so I won't laboriously go over it here. The arg flags in wkhtmltopdf translate to Zoom = 75% and 0 width margins (the -B, -L, etc are short hand for bottom, left, etc). The wkhtmltopdf documention is also quite good.
Edited: Credit for the render function goes to Matthias Eisen. Usage:
Assuming a template at /some/path/my_tpl.html, containing:
Hello {{ firstname }} {{ lastname }}!
context = {
'firstname': 'John',
'lastname': 'Doe'
}
result = render('/some/path/my_tpl.html', context)
print(result)
Hello John Doe!
