relationalai.std.strings.split()

split(string: str|Producer, separator: str|Producer) -> tuple[Expression]

Splits a string into substrings based on a separator. Returns a tuple of two Expression objects, where the first produces the index of the substring and the second produces the substring itself. If string or separator is a Producer, then split() 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.

Returns

A tuple of two Expression objects.

Example

Use split() to split a string into substrings 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 splitting the name property.
with model.rule():
    person = Person()
    index, substring = strings.split(person.full_name, " ")
    # Set first_name to the substring with index 0.
    with index == 0:
        person.set(first_name=substring)
    # Set last_name to the substring with index 1.
    with index == 1:
        person.set(last_name=substring)

# Since split() 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_part()
• join()