ReportLab

Links

• http://reportlab.com is the projects main website
• the "guide" conveniently in pdf format (generated by ReportLab itself one would imagine ;)
• a helpful tutorial

ReportLab is a hybrid free-software / commercial enterprise. The core python library is published with a Free Software License. On top of this a commercial company exists that offers products such as tools that work with RML, a specialized markup language. That said, alternative free software alternatives exist (made from a larger user community) to process RML, as well as the possibility to make your own.

Hello world

Nice demo of the "page as canvas" "low-level" way of working with ReportLab.

from reportlab.pdfgen import canvas
 
c = canvas.Canvas("hello.pdf")
c.drawString(100, 100, "Hello WORLD!")
c.save()

Creates a pdf from a .txt file.

From the Report Lab How to PDF:

The pdfgen package is the lowest level interface for generating PDF documents. A pdfgen program is essentially a sequence of instructions for "painting" a document onto a sequence of pages. The interface object which provides the painting operations is the pdfgen canvas.

The Canvas constructor:

def __init__(self,filename,
    pagesize=(595.27,841.89),
    bottomup = 1,
    pageCompression=0,
    encoding=rl_config.defaultEncoding,
    verbosity=0
    encrypt=None):

pageloop

This is a loop that opens a PDF with report lab ...

from reportlab.pdfgen.canvas import Canvas
from reportlab.lib.pagesizes import letter, A4
from reportlab.lib.units import inch, cm
import sys
from reportlab.pdfbase.ttfonts import TTFont, pdfmetrics

fontpath = "OSP-DIN.ttf"
font =  TTFont('MyFontName', fontpath)
pdfmetrics.registerFont(font)
c = Canvas("pageloop.pdf", pagesize=A4)

for i in range(1000):
    c.setPageSize(A4)
    c.setFont('MyFontName', 72)
    # c.drawString(10*cm, 0.5*cm, "Page {0}".format(i))
    c.drawCentredString(A4[0]/2, A4[1]/2, "Page {0}".format(i))
    c.showPage()
c.save()

File:ReporLabPageloop.pdf

pageloop with different sizes

from reportlab.pdfgen.canvas import Canvas
from reportlab.lib.pagesizes import A4, A5
from reportlab.lib.units import cm
from reportlab.pdfbase.ttfonts import TTFont, pdfmetrics
import sys


pdfmetrics.registerFont(TTFont('din', "OSP-DIN.ttf"))
pdfmetrics.registerFont(TTFont('lib', "Libertinage-x.ttf"))
c = Canvas("pageloopdifferentsizes.pdf", pagesize=A4)

for i in range(1000):
    if i%2==0:
        ps = A4
        c.setFont('din', 144)    
    else:
        ps = A5
        c.setFont('lib', 72)
    c.setPageSize(ps)    
    # c.drawString(10*cm, 0.5*cm, "Page {0}".format(i))
    c.drawCentredString(ps[0]/2, ps[1]/2, "Page {0}".format(i))
    c.showPage()
c.save()

SimpleDocTemplate

The "Platypus" system is a "higher level" interface that takes care of such niceties as creating "flowable" text (so you don't need to position every line yourself.

from reportlab.lib.pagesizes import A4
from reportlab.platypus import SimpleDocTemplate, Paragraph, Spacer
from reportlab.lib.styles import getSampleStyleSheet

doc = SimpleDocTemplate("text.pdf", pagesize=A4,
                        rightMargin=72, leftMargin=72,
                        topMargin=72, bottomMargin=18)


content = []
styles = getSampleStyleSheet()

for line in open('file.txt'):
    line = line.strip()
    if line:
        p = Paragraph('<font size=12>'+line+'</font>', styles["Normal"])
        content.append(p)
        content.append(Spacer(1, 12))

doc.build(content)

Using Platypus to do a 2 column layout with "flowables"

Example: Jekyll & Hyde meet Platypus

from reportlab.platypus import *
from reportlab.lib.styles import getSampleStyleSheet
from reportlab.rl_config import defaultPageSize

from reportlab.lib.pagesizes import A4
from reportlab.lib.units import inch, cm
import sys
import html5lib


leftPadding = 6
rightPadding = 6
bottomPadding = 6
topPadding = 6

pagew, pageh = A4
framew = (pagew / 2) - leftPadding - rightPadding
frameh = pageh - topPadding - bottomPadding
leftColumn = Frame(0, 0, framew, frameh, leftPadding, bottomPadding, rightPadding, topPadding, id="leftColumn")
rightColumn = Frame((pagew/2), 0, framew, frameh, leftPadding, bottomPadding, rightPadding, topPadding, id="rightColumn")
styles = getSampleStyleSheet()
elements = []

def header(txt):
    s = Spacer(0.2*inch, 0.3*inch)
    elements.append(s)
    para = Paragraph(txt, styles["Heading1"])
    elements.append(para)

def p(txt):
    s = Spacer(0.2*inch, 0.1*inch)
    elements.append(s)
    para = Paragraph(txt, styles["Normal"])
    elements.append(para)

# NOT USED
# def pre(txt):
#     s = Spacer(0.1*inch, 0.1*inch)
#     elements.append(s)
#     p = Preformatted(txt, styles["Code"])
#     elements.append(p)

# Read the HTML and "perform" the h1 and p elements
with open("jekyll.html") as f:
    t = html5lib.parse(f, treebuilder="etree", namespaceHTMLElements=False)
    for elt in t.find(".//body"):
        if elt.tag == "h1":
            header(elt.text)
        elif elt.tag == "p":
            p(elt.text)

twoColumnPage = PageTemplate(id="base", frames=[leftColumn, rightColumn], pagesize=A4)
doc = BaseDocTemplate("jekyll.pdf", pageTemplates=[twoColumnPage])
# elements.insert(0,Spacer(0,inch))
# doc = SimpleDocTemplate('gfe.pdf')
doc.build(elements)

Result: jekyll.pdf

Example: SICV Random Walk

http://guttormsgaard.activearchives.org/cgi-bin/walk.cgi

RML

RML is a report-lab specific document markup language similar to HTML but much more limited (and specific to the capabilities of Report Lab). The "official" tools to process RML and produce PDFs are commercial, but there exist alternative open source implementations based on the open source report lab library.

• trml2pdf gitlab
• z3c

Flexbox

http://reportlab-flexbox.readthedocs.io/en/latest/overview.html

Sverker Sjöberg has implemented an extension library for ReportLab that implments a "FlexBox".