otp.Source.add_prefix#

Source.add_prefix(prefix, inplace=False, columns=None, ignore_columns=None)#

Adds prefix to all column names (except TIMESTAMP (or Time) special column).

Parameters:

  • prefix (str) – String prefix to add to all columns.

  • inplace (bool) – The flag controls whether operation should be applied inplace or not. If inplace=True, then it returns nothing. Otherwise method returns a new modified object.

  • columns (list[str], optional) – If set, only selected columns will be updated with prefix. Can’t be used with ignore_columns parameter.

  • ignore_columns (list[str], optional) – If set, selected columns won’t be updated with prefix. Can’t be used with columns parameter.

  • self (Source)

Return type:

Source or None

Examples

Add prefix test_ to all columns (note that column Time is not renamed):

>>> data = otp.DataSource(db='US_COMP_SAMPLE', tick_type='TRD', symbols='AAPL')
>>> data = data[['PRICE', 'SIZE']][:3]
>>> data = data.add_prefix('test_')
>>> otp.run(data, date=otp.dt(2024, 2, 1))
                           Time  test_PRICE  test_SIZE
0 2024-02-01 04:00:00.008283417      186.50          6
1 2024-02-01 04:00:00.008290927      185.59          1
2 2024-02-01 04:00:00.008291153      185.49        107

Parameter columns specifies columns to be updated with prefix:

>>> data = otp.Tick(A=1, B=2, C=3, D=4, E=5)
>>> data = data.add_prefix('test_', columns=['A', 'B', 'C'])
>>> otp.run(data)
        Time  test_A  test_B  test_C  D  E
0 2003-12-01       1       2       3  4  5

Parameter ignore_columns specifies columns to ignore:

>>> data = otp.Tick(A=1, B=2, C=3, D=4, E=5)
>>> data = data.add_prefix('test_', ignore_columns=['A', 'B', 'C'])
>>> otp.run(data)
        Time  A  B  C  test_D  test_E
0 2003-12-01  1  2  3       4       5

Parameters columns and ignore_columns can’t be used at the same time:

>>> data = otp.Tick(A=1, B=2, C=3, D=4, E=5)
>>> data.add_prefix('test_', columns=['B', 'C'], ignore_columns=['A'])
Traceback (most recent call last):
    ...
ValueError: It is allowed to use only one of `columns` or `ignore_columns` parameters at a time

Columns can’t be renamed if their resulting name will be equal to existing column name:

>>> data = otp.Tick(X=1, XX=2)
>>> data.add_prefix('X', columns=['X'])
Traceback (most recent call last):
    ...
AttributeError: Column XX already exists, please, use another prefix