otp.ops.declare_string_size#

declare_string_size(expression, size)#

This function is used to indicate the maximum size of the string returned by expression.

This function is especially useful in SQL queries in which some output fields are expressions that return strings. In those SQL queries, use of declare_string_size() around such expressions is the only way to ensure that output string fields will be sufficiently wide for the entire output value.

Parameters:

expression (str, Operation)
size (int)

Return type:

Operation

Examples

Limit the length of the string expression:

>>> data = otp.Ticks(A=['hello', 'world!'])
>>> data['X'] = otp.ops.declare_string_size(data['A'].str.repeat(3), 10)
>>> otp.run(data)
                     Time       A           X
0 2003-12-01 00:00:00.000   hello  hellohello
1 2003-12-01 00:00:00.001  world!  world!worl