relationalai.std.re.search()

search(regex: str|Producer, string: str|Producer) -> Match

Scans a string for a regular expression match and returns a Match object for the first match found. If regex or string is a Producer, then search() filters out non-string regex values and non-matching string values from the producers. Must be used in a rule or query context.

Tip

When passing a string literal, use a raw string — which is prefaced with an r, as in r"J.*" — to avoid escaping special characters in regular expressions.

Parameters

Name	Type	Description
regex	Producer or Python str	A regular expression string.
string	Producer or Python str	The string to search.

Returns

A Match object.

Example

Use the search() function to search for a substring that matches a regular expression anywhere in a string:

#
import relationalai as rai
from relationalai.std import alias, re


# =====
# SETUP
# =====

model = rai.Model("MyModel4")
Message = model.Type("Message")

with model.rule():
    Message.add(id=1).set(text="The party starts at 8:00 PM.")
    Message.add(id=2).set(text="Bring tacos")
    Message.add(id=3).set(text=-1)  # Non-string text


# =======
# EXAMPLE
# =======

with model.rule():
    message = Message()
    # Filter messages that contain a time in the format "HH:MM AM/PM".
    match = re.search(r"\d{1,2}:\d{2} [AP]M", message.text)
    # Since search() filters out non-matching strings and non-string values,
    # the following does not set properties for the messages with IDs 2 and 3.
    message.set(match=match, match_start=match.start(), match_end=match.end())

with model.query() as select:
    message = Message()
    response = select(
        message.id,
        message.text,
        message.match,
        message.match_start,
        message.match_end,
    )

print(response.results)
#    id                          text    match  match_start  match_end
# 0   1  The party starts at 8:00 PM.  8:00 PM         20.0       27.0
# 1   2                   Bring tacos      NaN          NaN        NaN
# 2   3                            -1      NaN          NaN        NaN

See Also

• match()
• fullmatch()
• findall()
• sub()