# Examples

The examples subdirectory contains examples (based on the simple C++ examples) showing how to use the Python bindings: simpleindex.py, simplesearch.py, simpleexpand.py. There’s also simplematchdecider.py which shows how to define a MatchDecider in Python.

## simplesearch.py

     1#!/usr/bin/env python
     2#
     3# Simple command-line search script.
     4#
     5# Copyright (C) 2003 James Aylett
     6# Copyright (C) 2004,2007,2009,2013 Olly Betts
     7#
     8# This program is free software; you can redistribute it and/or
     9# modify it under the terms of the GNU General Public License as
    10# published by the Free Software Foundation; either version 2 of the
    11# License, or (at your option) any later version.
    12#
    13# This program is distributed in the hope that it will be useful,
    14# but WITHOUT ANY WARRANTY; without even the implied warranty of
    15# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    16# GNU General Public License for more details.
    17#
    18# You should have received a copy of the GNU General Public License
    19# along with this program; if not, see
    20# <https://www.gnu.org/licenses/>.
    21
    22import sys
    23import xapian
    24
    25# We require at least two command line arguments.
    26if len(sys.argv) < 3:
    27    print("Usage: %s PATH_TO_DATABASE QUERY" % sys.argv[0], file=sys.stderr)
    28    sys.exit(1)
    29
    30try:
    31    # Open the database for searching.
    32    database = xapian.Database(sys.argv[1])
    33
    34    # Start an enquire session.
    35    enquire = xapian.Enquire(database)
    36
    37    # Combine the rest of the command line arguments with spaces between
    38    # them, so that simple queries don't have to be quoted at the shell
    39    # level.
    40    query_string = str.join(' ', sys.argv[2:])
    41
    42    # Parse the query string to produce a Xapian::Query object.
    43    qp = xapian.QueryParser()
    44    stemmer = xapian.Stem("english")
    45    qp.set_stemmer(stemmer)
    46    qp.set_database(database)
    47    qp.set_stemming_strategy(xapian.QueryParser.STEM_SOME)
    48    query = qp.parse_query(query_string)
    49    print("Parsed query is: %s" % str(query))
    50
    51    # Find the top 10 results for the query.
    52    enquire.set_query(query)
    53    matches = enquire.get_mset(0, 10)
    54
    55    # Display the results.
    56    print("%i results found." % matches.get_matches_estimated())
    57    print("Results 1-%i:" % matches.size())
    58
    59    for m in matches:
    60        print("%i: %i%% docid=%i [%s]" % (m.rank + 1, m.percent, m.docid, m.document.get_data().decode('utf-8')))
    61
    62except Exception as e:
    63    print("Exception: %s" % str(e), file=sys.stderr)
    64    sys.exit(1)

## simpleindex.py

     1#!/usr/bin/env python
     2#
     3# Index each paragraph of a text file as a Xapian document.
     4#
     5# Copyright (C) 2003 James Aylett
     6# Copyright (C) 2004,2007,2013,2014 Olly Betts
     7#
     8# This program is free software; you can redistribute it and/or
     9# modify it under the terms of the GNU General Public License as
    10# published by the Free Software Foundation; either version 2 of the
    11# License, or (at your option) any later version.
    12#
    13# This program is distributed in the hope that it will be useful,
    14# but WITHOUT ANY WARRANTY; without even the implied warranty of
    15# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    16# GNU General Public License for more details.
    17#
    18# You should have received a copy of the GNU General Public License
    19# along with this program; if not, see
    20# <https://www.gnu.org/licenses/>.
    21
    22import sys
    23import xapian
    24import string
    25
    26if len(sys.argv) != 2:
    27    print("Usage: %s PATH_TO_DATABASE" % sys.argv[0], file=sys.stderr)
    28    sys.exit(1)
    29
    30try:
    31    # Open the database for update, creating a new database if necessary.
    32    database = xapian.WritableDatabase(sys.argv[1], xapian.DB_CREATE_OR_OPEN)
    33
    34    indexer = xapian.TermGenerator()
    35    stemmer = xapian.Stem("english")
    36    indexer.set_stemmer(stemmer)
    37
    38    para = ''
    39    try:
    40        for line in sys.stdin:
    41            line = line.strip()
    42            if line == '':
    43                if para != '':
    44                    # We've reached the end of a paragraph, so index it.
    45                    doc = xapian.Document()
    46                    doc.set_data(para)
    47
    48                    indexer.set_document(doc)
    49                    indexer.index_text(para)
    50
    51                    # Add the document to the database.
    52                    database.add_document(doc)
    53                    para = ''
    54            else:
    55                if para != '':
    56                    para += ' '
    57                para += line
    58    except StopIteration:
    59        pass
    60
    61except Exception as e:
    62    print("Exception: %s" % str(e), file=sys.stderr)
    63    sys.exit(1)

## simpleexpand.py

     1#!/usr/bin/env python
     2#
     3# Simple example script demonstrating query expansion.
     4#
     5# Copyright (C) 2003 James Aylett
     6# Copyright (C) 2004,2006,2007,2012,2013,2014 Olly Betts
     7#
     8# This program is free software; you can redistribute it and/or
     9# modify it under the terms of the GNU General Public License as
    10# published by the Free Software Foundation; either version 2 of the
    11# License, or (at your option) any later version.
    12#
    13# This program is distributed in the hope that it will be useful,
    14# but WITHOUT ANY WARRANTY; without even the implied warranty of
    15# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    16# GNU General Public License for more details.
    17#
    18# You should have received a copy of the GNU General Public License
    19# along with this program; if not, see
    20# <https://www.gnu.org/licenses/>.
    21
    22import sys
    23import xapian
    24
    25# We require at least two command line arguments.
    26if len(sys.argv) < 3:
    27    print("Usage: %s PATH_TO_DATABASE QUERY [-- [DOCID...]]" % sys.argv[0], file=sys.stderr)
    28    sys.exit(1)
    29
    30try:
    31    # Open the database for searching.
    32    database = xapian.Database(sys.argv[1])
    33
    34    # Start an enquire session.
    35    enquire = xapian.Enquire(database)
    36
    37    # Combine command line arguments up to "--" with spaces between
    38    # them, so that simple queries don't have to be quoted at the shell
    39    # level.
    40    query_string = sys.argv[2]
    41    index = 3
    42    while index < len(sys.argv):
    43        arg = sys.argv[index]
    44        index += 1
    45        if arg == '--':
    46            # Passed marker, move to parsing relevant docids.
    47            break
    48        query_string += ' '
    49        query_string += arg
    50
    51    # Create an RSet with the listed docids in.
    52    reldocs = xapian.RSet()
    53    for index in range(index, len(sys.argv)):
    54        reldocs.add_document(int(sys.argv[index]))
    55
    56    # Parse the query string to produce a Xapian::Query object.
    57    qp = xapian.QueryParser()
    58    stemmer = xapian.Stem("english")
    59    qp.set_stemmer(stemmer)
    60    qp.set_database(database)
    61    qp.set_stemming_strategy(xapian.QueryParser.STEM_SOME)
    62    query = qp.parse_query(query_string)
    63
    64    if not query.empty():
    65        print("Parsed query is: %s" % str(query))
    66
    67        # Find the top 10 results for the query.
    68        enquire.set_query(query)
    69        matches = enquire.get_mset(0, 10, reldocs)
    70
    71        # Display the results.
    72        print("%i results found." % matches.get_matches_estimated())
    73        print("Results 1-%i:" % matches.size())
    74
    75        for m in matches:
    76            print("%i: %i%% docid=%i [%s]" % (m.rank + 1, m.percent, m.docid, m.document.get_data()))
    77
    78    # Put the top 5 (at most) docs into the rset if rset is empty
    79    if reldocs.empty():
    80        rel_count = 0
    81        for m in matches:
    82            reldocs.add_document(m.docid)
    83            rel_count += 1
    84            if rel_count == 5:
    85                break
    86
    87    # Get the suggested expand terms
    88    eterms = enquire.get_eset(10, reldocs)
    89    print("%i suggested additional terms" % eterms.size())
    90    for k in eterms:
    91        print("%s: %f" % (k.term, k.weight))
    92
    93except Exception as e:
    94    print("Exception: %s" % str(e), file=sys.stderr)
    95    sys.exit(1)

## simplematchdecider.py

     1#!/usr/bin/env python
     2#
     3# Simple command-line match decider example
     4#
     5# Copyright (C) 2003 James Aylett
     6# Copyright (C) 2004,2007,2009,2013 Olly Betts
     7#
     8# This program is free software; you can redistribute it and/or
     9# modify it under the terms of the GNU General Public License as
    10# published by the Free Software Foundation; either version 2 of the
    11# License, or (at your option) any later version.
    12#
    13# This program is distributed in the hope that it will be useful,
    14# but WITHOUT ANY WARRANTY; without even the implied warranty of
    15# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    16# GNU General Public License for more details.
    17#
    18# You should have received a copy of the GNU General Public License
    19# along with this program; if not, see
    20# <https://www.gnu.org/licenses/>.
    21
    22import sys
    23import xapian
    24
    25# This example runs a query like simplesearch does, but uses a MatchDecider
    26# (mymatchdecider) to discard any document for which value 0 is equal to
    27# the string passed as the second command line argument.
    28
    29if len(sys.argv) < 4:
    30    print("Usage: %s PATH_TO_DATABASE AVOID_VALUE QUERY" % sys.argv[0], file=sys.stderr)
    31    sys.exit(1)
    32
    33class mymatchdecider(xapian.MatchDecider):
    34    def __init__(self, avoidvalue):
    35        xapian.MatchDecider.__init__(self)
    36        self.avoidvalue = avoidvalue
    37
    38    def __call__(self, doc):
    39        return doc.get_value(0) != self.avoidvalue
    40
    41try:
    42    # Open the database for searching.
    43    database = xapian.Database(sys.argv[1])
    44
    45    # Start an enquire session.
    46    enquire = xapian.Enquire(database)
    47
    48    # Combine the rest of the command line arguments with spaces between
    49    # them, so that simple queries don't have to be quoted at the shell
    50    # level.
    51    avoid_value = sys.argv[2]
    52    query_string = str.join(' ', sys.argv[3:])
    53
    54    # Parse the query string to produce a Xapian::Query object.
    55    qp = xapian.QueryParser()
    56    stemmer = xapian.Stem("english")
    57    qp.set_stemmer(stemmer)
    58    qp.set_database(database)
    59    qp.set_stemming_strategy(xapian.QueryParser.STEM_SOME)
    60    query = qp.parse_query(query_string)
    61    print("Parsed query is: %s" % str(query))
    62
    63    # Find the top 10 results for the query.
    64    enquire.set_query(query)
    65    mdecider = mymatchdecider(avoid_value)
    66    matches = enquire.get_mset(0, 10, None, mdecider)
    67
    68    # Display the results.
    69    print("%i results found." % matches.get_matches_estimated())
    70    print("Results 1-%i:" % matches.size())
    71
    72    for m in matches:
    73        print("%i: %i%% docid=%i [%s]" % (m.rank + 1, m.percent, m.docid, m.document.get_data()))
    74
    75except Exception as e:
    76    print("Exception: %s" % str(e), file=sys.stderr)
    77    sys.exit(1)