General Functions¶

General-purpose functions for value retrieval, formatting, and conditional logic.

from everysk.sdk.engines import Expression
expression_engine = Expression()

Value Retrieval¶

port_attribute¶

port_attribute(arr, default=0.0)

Returns the single unique element in arr. Raises an exception if more than one distinct value is found. Returns default when the array is empty.

This function is typically used to extract portfolio-level attributes — such as NLV or reference date — that appear identically on every row of a data store.

import numpy as np

expression_engine.solve('port_attribute(arr)', {'arr': np.array([1000.0, 1000.0, 1000.0])})
# 1000.0

expression_engine.solve('port_attribute(arr)', {'arr': np.array(['USD', 'USD', 'USD'])})
# 'USD'

expression_engine.solve('port_attribute(arr)', {'arr': np.array([])})
# 0.0

single_value¶

single_value(arr, default=None)

Returns the unique value in arr, or default if the array contains more than one distinct value or is empty.

import numpy as np

expression_engine.solve('single_value(arr)', {'arr': np.array([5, 5, 5])})
# 5

expression_engine.solve('single_value(arr)', {'arr': np.array([1, 2, 3])})
# None

expression_engine.solve('single_value(arr, "mixed")', {'arr': np.array([1, 2, 3])})
# 'mixed'

single_number¶

single_number(arr)

Specialization of single_value that first casts the array to float. Returns 0.0 if the array has more than one distinct value or is empty.

import numpy as np

expression_engine.solve('single_number(arr)', {'arr': np.array([42, 42, 42])})
# 42.0

expression_engine.solve('single_number(arr)', {'arr': np.array([1, 2, 3])})
# 0.0

single_text¶

single_text(arr)

Specialization of single_value that first casts the array to str. Returns '-' if the array has more than one distinct value or is empty.

import numpy as np

expression_engine.solve('single_text(arr)', {'arr': np.array(['BRL', 'BRL', 'BRL'])})
# 'BRL'

expression_engine.solve('single_text(arr)', {'arr': np.array(['BRL', 'USD'])})
# '-'

multiple_text¶

multiple_text(arr, delimiter=',')

Joins the unique elements of arr into a single string, separated by delimiter. Duplicate values are deduplicated and None values are dropped. Returns '-' if no valid values remain.

import numpy as np

expression_engine.solve('multiple_text(arr)', {'arr': np.array(['Equity', 'Bond', 'Equity'])})
# 'Equity, Bond'

expression_engine.solve('multiple_text(arr, " |")', {'arr': np.array(['a', 'b', 'c'])})
# 'a | b | c'

Formatting¶

to_format¶

to_format(value, format)

Vectorized. Formats value into a display string using a format specifier. Returns None if value is None.

The format string combines a type code with an optional decimal precision:

Format	Description	Example input	Example output
`N`	Number	`1.2345` with `N2`	`'1.23'`
`%`	Percentage	`0.2345` with `%2`	`'23.45%'`
`$`	Currency	`123.456` with `$2`	`'$123.46'`
`$S`	Short currency	`123456.789` with `$S2`	`'$123 456.79'`
`$LN`	Currency with notation	`123456.789` with `$LN2`	`'$123.46K'`
`LN`	Long notation	`123456.789` with `LN2`	`'123.46K'`
`S`	Space-separated	`123456.789` with `S0`	`'123 457'`
`D`	Date

expression_engine.solve('to_format(1.2345, "N2")')
# '1.23'

expression_engine.solve('to_format(0.234567, "%2")')
# '23.46%'

expression_engine.solve('to_format(123456.789, "$LN0")')
# '$123K'

import numpy as np
expression_engine.solve('to_format(values, "N2")', {
    'values': np.array([1.2345, 0.234567, 123.456])
})
# ['1.23', '0.23', '123.46']

Array Cleaning¶

drop_none¶

drop_none(arr)

Removes all None values from arr.

import numpy as np

expression_engine.solve('drop_none(arr)', {'arr': np.array([1, None, 2, None, 3])})
# [1, 2, 3]

expression_engine.solve('drop_none(arr)', {'arr': np.array(['a', None, 'b'])})
# ['a', 'b']

Conditional Logic¶

conditional¶

conditional(cond_1, value_if_cond_1, …, cond_n, value_if_cond_n, default)

Evaluates conditions left to right and returns the value paired with the first condition that is True. Returns default when no condition matches.

This is equivalent to a chain of if / elif / else statements. Arguments alternate between conditions and values, ending with a single default.

expression_engine.solve('conditional(False, "a", False, "b", "c")')
# 'c'

expression_engine.solve('conditional(True, "a", False, "b", "c")')
# 'a'

expression_engine.solve('conditional(False, "a", True, "b", "c")')
# 'b'