Source code for

# coding: utf-8
#TODO: Write module doc.

from __future__ import division, unicode_literals, absolute_import

import re
from import zopen, reverse_readfile
import collections

__author__ = 'Shyue Ping Ong'
__copyright__ = 'Copyright 2013, The Materials Virtual Lab'
__version__ = '0.1'
__maintainer__ = 'Shyue Ping Ong'
__email__ = ''
__date__ = '6/2/15'

[docs]def regrep(filename, patterns, reverse=False, terminate_on_match=False, postprocess=str): """ A powerful regular expression version of grep. Args: filename (str): Filename to grep. patterns (dict): A dict of patterns, e.g., {"energy": "energy\(sigma->0\)\s+=\s+([\d\-\.]+)"}. reverse (bool): Read files in reverse. Defaults to false. Useful for large files, especially when used with terminate_on_match. terminate_on_match (bool): Whether to terminate when there is at least one match in each key in pattern. postprocess (callable): A post processing function to convert all matches. Defaults to str, i.e., no change. Returns: A dict of the following form: {key1: [[[matches...], lineno], [[matches...], lineno], [[matches...], lineno], ...], key2: ...} For reverse reads, the lineno is given as a -ve number. Please note that 0-based indexing is used. """ compiled = {k: re.compile(v) for k, v in patterns.items()} matches = collections.defaultdict(list) gen = reverse_readfile(filename) if reverse else zopen(filename, "rt") for i, l in enumerate(gen): for k, p in compiled.items(): m = if m: matches[k].append([[postprocess(g) for g in m.groups()], -i if reverse else i]) if terminate_on_match and all([ len(matches.get(k, [])) for k in compiled.keys()]): break try: # Try to close open file handle. Pass if it is a generator. gen.close() except: pass return matches