Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.11/site-packages/pandas/api/internals.py: 60%

1import numpy as np 

2 

3from pandas._typing import ArrayLike 

4 

5from pandas import ( 

6 DataFrame, 

7 Index, 

8) 

9from pandas.core.internals.api import _make_block 

10from pandas.core.internals.managers import BlockManager as _BlockManager 

11 

12 

13def create_dataframe_from_blocks( 

14 blocks: list[tuple[ArrayLike, np.ndarray]], index: Index, columns: Index 

15) -> DataFrame: 

16 """ 

17 Low-level function to create a DataFrame from arrays as they are 

18 representing the block structure of the resulting DataFrame. 

19 

20 Attention: this is an advanced, low-level function that should only be 

21 used if you know that the below-mentioned assumptions are guaranteed. 

22 If passing data that do not follow those assumptions, subsequent 

23 operations on the resulting DataFrame might lead to strange errors. 

24 For almost all use cases, you should use the standard pd.DataFrame(..) 

25 constructor instead. If you are planning to use this function, let us 

26 know by opening an issue at https://github.com/pandas-dev/pandas/issues. 

27 

28 Assumptions: 

29 

30 - The block arrays are either a 2D numpy array or a pandas ExtensionArray 

31 - In case of a numpy array, it is assumed to already be in the expected 

32 shape for Blocks (2D, (cols, rows), i.e. transposed compared to the 

33 DataFrame columns). 

34 - All arrays are taken as is (no type inference) and expected to have the 

35 correct size. 

36 - The placement arrays have the correct length (equalling the number of 

37 columns that its equivalent block array represents), and all placement 

38 arrays together form a complete set of 0 to n_columns - 1. 

39 

40 Parameters 

41 ---------- 

42 blocks : list of tuples of (block_array, block_placement) 

43 This should be a list of tuples existing of (block_array, block_placement), 

44 where: 

45 

46 - block_array is a 2D numpy array or a 1D ExtensionArray, following the 

47 requirements listed above. 

48 - block_placement is a 1D integer numpy array 

49 index : Index 

50 The Index object for the `index` of the resulting DataFrame. 

51 columns : Index 

52 The Index object for the `columns` of the resulting DataFrame. 

53 

54 Returns 

55 ------- 

56 DataFrame 

57 """ 

58 block_objs = [_make_block(*block) for block in blocks] 

59 axes = [columns, index] 

60 mgr = _BlockManager(block_objs, axes) 

61 return DataFrame._from_mgr(mgr, mgr.axes)