otp.Source.add_suffix#

Source.add_suffix(suffix, inplace=False, columns=None, ignore_columns=None)#

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

Parameters

  • suffix (str) – String suffix 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 suffix. Can’t be used with ignore_columns parameter.

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

  • self (Source) –

Return type

Source or None

Examples

Add suffix _test to all columns (note that column Time is not renamed):

>>> data = otp.DataSource(db='US_COMP', tick_type='TRD', symbols='AAPL')
>>> data = data.add_suffix('_test')
>>> otp.run(data, start=otp.dt(2022, 3, 1), end=otp.dt(2022, 3, 2))
                     Time  PRICE_test  SIZE_test
0 2022-03-01 00:00:00.000         1.3        100
1 2022-03-01 00:00:00.001         1.4         10
2 2022-03-01 00:00:00.002         1.4         50

Parameter columns specifies columns to be updated with suffix:

>>> data = otp.Tick(A=1, B=2, C=3, D=4, E=5)
>>> data = data.add_suffix('_test', columns=['A', 'B', 'C'])
>>> otp.run(data)
        Time  A_test  B_test  C_test  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_suffix('_test', ignore_columns=['A', 'B', 'C'])
>>> otp.run(data)
        Time  A  B  C  D_test  E_test
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_suffix('_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_suffix('X', columns=['X'])
Traceback (most recent call last):
    ...
AttributeError: Column XX already exists, please, use another suffix