Converting Python script for QGIS?

Question

I am still a novice in python, but I have the long term goal to create a plugin one day. The first step to this plugin is a test with QGIS python scripts to convert an Access mdb into sqlite db and then to proceed from there.

I found a python script here that will dump an Access mdb into a sqlite db.

The script is normally called from commandline with this patter: python AccessDump.py access.mdb | sqlite3 new.db

I now try to change the script, so i can run it as a QGIS script from the Processing Toolbox, but I really lack the basics so far.

Original script:

#!/usr/bin/env python
#
# AccessDump.py
# A simple script to dump the contents of a Microsoft Access Database.
# It depends upon the mdbtools suite:
#   http://sourceforge.net/projects/mdbtools/

import sys, subprocess, os

DATABASE = sys.argv[1]

# Dump the schema for the DB
subprocess.call(["mdb-schema", DATABASE, "mysql"])

# Get the list of table names with "mdb-tables"
table_names = subprocess.Popen(["mdb-tables", "-1", DATABASE],
                               stdout=subprocess.PIPE).communicate()[0]
tables = table_names.splitlines()

print "BEGIN;" # start a transaction, speeds things up when importing
sys.stdout.flush()

# Dump each table as a CSV file using "mdb-export",
# converting " " in table names to "_" for the CSV filenames.
for table in tables:
    if table != '':
        subprocess.call(["mdb-export", "-I", "mysql", DATABASE, table])

print "COMMIT;" # end the transaction
sys.stdout.flush()

I already understood the basic mechanism to first read out the table schema of the .mdb for each table, and then export tables content into the newly created db. However, I have no clue how to change the script so that I do not need that | sqlite3 new.db - part from the original shell command, but integrate it into the script, respectivly change new.db to be the output variable from the script dialog.

##Database=group
##Access.mdb to SqLite=name
##inputmdb= input file
##outputsqlite = output file

Answer 1

This should work:

##Database=group
##Access.mdb to SqLite=name
##inputmdb= input file
##outputsqlite = output file

import sys, subprocess, os, sqlite3 as sql

mdb_name = inputmdb
sql_name = outputsqlite

try:
    print "\nopening db"
    conn = sql.connect(sql_name)
    curs = conn.cursor()

    print "\ncreating schema"
    cmds = subprocess.Popen(["mdb-schema", mdb_name, "mysql"], stdout=subprocess.PIPE).communicate()[0]
    curs.executescript(cmds)
    conn.commit()

    print "\nfetching table names"
    table_names = subprocess.Popen(["mdb-tables", "-1", mdb_name], stdout=subprocess.PIPE).communicate()[0]
    tables = table_names.splitlines()

    print "\npopulate tables"
    for table in tables:
        if table != '':
            cmds = subprocess.Popen(["mdb-export", "-I", "mysql", mdb_name, table], stdout=subprocess.PIPE).communicate()[0]
            curs.executescript("BEGIN;" + cmds + "COMMIT;")
    conn.commit()
    print "\nhoooray"

except Exception, e:
    print "oh noes:"
    print e
finally:    
    print "\nclosing DB"
    conn.close()