replus
A wrapper for Python's re library for advanced regex pattern management
Installation
pip install replus
or clone this repo
[email protected]:raptored01/replus.git
and then run
python setup.py install
Basic usage
The Engine loads Regular Expression pattern templates written in *.json files from the provided directory, builds and compiles them in the following fashion:
example of template models/dates.json
:
{
"day": [
"3[01]",
"[12][0-9]",
"0?[1-9]"
],
"month": [
"0?[1-9]",
"1[012]"
],
"year": [
"\\d{4}"
],
"date": [
"{{day}}/{{month}}/{{year}}",
"{{year}}-{{month}}-{{day}}"
],
"patterns": [
"{{date}}"
]
}
will result in the following regex:
(?P<date_0>(?P<day_0>[12][0-9]|0?[1-9]|3[01])/(?P<month_0>0?[1-9]|1[012])/(?P<year_0>\d{4})|(?P<year_1>\d{4})-(?P<month_1>0?[1-9]|1[012])-(?P<day_1>[12][0-9]|0?[1-9]|3[01]))
It is possible to query as follows:
from replus import Engine
engine = Engine('models')
for match in engine.parse("Look at this date: 2012-20-10"):
print(match)
# <[Match date] span(19, 29): 2012-12-10>
date = match.group('date')
print(date)
# <[Group date_0] span(19, 29): 2012-12-10>
day = date.group('day')
print(day)
# <[Group day_1] span(27, 29): 10>
month = date.group('month')
print(month)
# <[Group month_1] span(24, 26): 12>
year = date.group('year')
print(year)
# [Group year_1] span(19, 23): 2012>
Match objects have the following attributes:
- type: the type of match (e.g. "dates");
- match: the re.match object;
- re: the regex pattern;
- all_group_names: the name of all the children groups;
Both Match and Group objects have the following attributes:
- value: the string value of the match/group
- start: the beginning of the match/group relative to the input string
- end: the end of the group relative to the input string
- offset (start, end)
- length (end-start)
Group objects have the following attributes:
- name: the actual group name (e.g. date_1);
- key: the group key (e.g. date);
Both Match and Group objects can be serialized in dicts with the serialize()
method and
to a json string with the json
attribute
Secondary features
There are two useful secondary features:
non-capturing groups
: these are specified by using the "!" prefix in the group namedynamic backreferences
: use#
to reference a previous group and@<n>
to specify how many groups behind
template:
{
"!number": [
"\\d"
],
"abg": [
"alpha",
"beta",
"gamma"
],
"patterns": [
"This is an unnamed number group: {{number}}.",
"I can match {{abg}} and {{abg}}, and then re-match the last {{#abg}} or the second last {{#abg@2}}"
]
}
It will generate the following regexs:
This is an unnamed number group: (?:\d).
I can match (?P<abg_0>alpha|gamma|beta) and (?P<abg_1>alpha|gamma|beta), and then re-match the last (?P=abg_1) or the second last (?P=abg_0)
N.B.: in order to obtain an escape char, such as \d
, in the pattern's model it must be double escaped: \\d
Current limitations
None known