relationalai.std.strings.split_part()

split_part(string: Producer, separator: str|Producer, index: int|Producer) -> Expression

Extracts a substring from a string that is split by a specified separator at a given index. If string or separator is a Producer, then split_part() acts as a filter and removes non-string values from the producer. Must be called in a rule or query context.

Parameters

Name	Type	Description
string	Producer or Python str object	The string to split.
separator	Producer or Python str object	The separator to split the string by.
index	Producer or Python int object	The index of the substring to extract.

Returns

An Expression object.

Example

Use split_part() to extract a substring at a specified index based on a separator:

import relationalai as rai
from relationalai.std import strings


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

model = rai.Model("MyModel")
Person = model.Type("Person")

with model.rule():
    Person.add(id=1).set(full_name="Alice Smith")
    Person.add(id=2).set(full_name="Bob Jones")
    Person.add(id=3).set(full_name=-1)  # Non-string full_name


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

# Set 'first_name' and 'last_name' properties by extracting parts of the 'full_name' property.
with model.rule():
    person = Person()
    person.set(
        first_name=strings.split_part(person.full_name, " ", 0),
        last_name=strings.split_part(person.full_name, " ", 1)
    )

# Since split_part() filters out non-string values, the first_name and last_name
# properties are not set for the person with id=3.
with model.query() as select:
    person = Person()
    response = select(person.id, person.first_name, person.last_name)

print(response.results)
#    id first_name last_name
# 0   1      Alice     Smith
# 1   2        Bob     Jones
# 2   3        NaN       NaN

See Also

• split()
• join()