Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.8/site-packages/pandas/core/array_algos/transforms.py: 19%

1""" 

2transforms.py is for shape-preserving functions. 

3""" 

4 

5from __future__ import annotations 

6 

7import numpy as np 

8 

9from pandas._typing import AxisInt 

10 

11 

12def shift(values: np.ndarray, periods: int, axis: AxisInt, fill_value) -> np.ndarray: 

13 new_values = values 

14 

15 if periods == 0 or values.size == 0: 

16 return new_values.copy() 

17 

18 # make sure array sent to np.roll is c_contiguous 

19 f_ordered = values.flags.f_contiguous 

20 if f_ordered: 

21 new_values = new_values.T 

22 axis = new_values.ndim - axis - 1 

23 

24 if new_values.size: 

25 new_values = np.roll( 

26 new_values, 

27 np.intp(periods), 

28 axis=axis, 

29 ) 

30 

31 axis_indexer = [slice(None)] * values.ndim 

32 if periods > 0: 

33 axis_indexer[axis] = slice(None, periods) 

34 else: 

35 axis_indexer[axis] = slice(periods, None) 

36 new_values[tuple(axis_indexer)] = fill_value 

37 

38 # restore original order 

39 if f_ordered: 

40 new_values = new_values.T 

41 

42 return new_values