Thursday, January 15, 2015

Publish databases to PDF with PyDAL and xtopdf

By Vasudev Ram

Some days ago, I had blogged about pyDAL, a pure Python Database Abstraction Layer.

Today I thought of writing a program to publish database data to PDF, using PyDAL and xtopdf, my open source Python library for PDF creation from other file formats.

(Here is a good online overview about xtopdf, for those new to it.)

So here is the code for
Author: Vasudev Ram
Copyright 2014 Vasudev Ram -
This program is a demo of how to use the PyDAL and xtopdf Python libraries 
together to publish database data to PDF.
PyDAL is at:
xtopdf is at:
and info about xtopdf is at: or 

# imports
from pydal import DAL, Field
from PDFWriter import PDFWriter

SEP = 60

# create the database
db = DAL('sqlite://house_depot.db')

# define the table
db.define_table('furniture', \
    Field('id'), Field('name'), Field('quantity'), Field('unit_price')

# insert rows into table
items = ( \
    (1, 'chair', 40, 50),
    (2, 'table', 10, 300),
    (3, 'cupboard', 20, 200),
    (4, 'bed', 30, 400)
for item in items:[0], name=item[1], quantity=item[2], unit_price=item[3])

# define the query
query =
# the above line shows an interesting property of PyDAL; it seems to 
# have some flexibility in how queries can be defined; in this case,
# just saying db.table_name tells it to fetch all the rows 
# from table_name; there are other variations possible; I have not 
# checked out all the options, but the ones I have seem somewhat 
# intuitive.

# run the query
rows = db(query).select()

# setup the PDFWriter
pw = PDFWriter('furniture.pdf')
pw.setFont('Courier', 10)
pw.setHeader('     House Depot Stock Report - Furniture Division     '.center(60))
pw.setFooter('Generated by xtopdf:')

pw.writeLine('=' * SEP)

field_widths = (5, 10, 10, 12, 10)

# print the header row
pw.writeLine(''.join([idx]) for idx, header_field in enumerate(('#', 'Name', 'Quantity', 'Unit price', 'Price'))))

pw.writeLine('-' * SEP)

# print the data rows
for row in rows:
    # methinks the writeLine argument gets a little long here ...
    # the first version of the program was taller but thinner :)
    pw.writeLine(''.join(str(data_field).center(field_widths[idx]) for idx, data_field in enumerate((row['id'], row['name'], row['quantity'], row['unit_price'], int(row['quantity']) * int(row['unit_price'])))))

pw.writeLine('=' * SEP)

I ran it (on Windows) with:
$ py 2>NUL
Here is a screenshot of the output in Foxit PDF Reader:

- Enjoy.

--- Posts about Python  ---  Posts about xtopdf ---

- Vasudev Ram - Python programming and training

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1 comment:

Vasudev Ram said...

I forgot to explicitly mention in this post, that PyDAL supports access to many popular databases, both open source and proprietary, like:

SQLite, PostgreSQL, MySQL, Oracle, MSSQL, FireBird, DB2, Informix, Ingres, Cubrid, Sybase, Teradata, SAPDB, MongoDB.