Coverage for nlp_manager/number.py: 87%

1""" 

2crate_anon/nlp_manager/number.py 

3 

4=============================================================================== 

5 

6 Copyright (C) 2015, University of Cambridge, Department of Psychiatry. 

7 Created by Rudolf Cardinal (rnc1001@cam.ac.uk). 

8 

9 This file is part of CRATE. 

10 

11 CRATE is free software: you can redistribute it and/or modify 

12 it under the terms of the GNU General Public License as published by 

13 the Free Software Foundation, either version 3 of the License, or 

14 (at your option) any later version. 

15 

16 CRATE is distributed in the hope that it will be useful, 

17 but WITHOUT ANY WARRANTY; without even the implied warranty of 

18 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 

19 GNU General Public License for more details. 

20 

21 You should have received a copy of the GNU General Public License 

22 along with CRATE. If not, see <https://www.gnu.org/licenses/>. 

23 

24=============================================================================== 

25 

26**Number conversion functions.** 

27 

28""" 

29 

30from typing import Optional 

31 

32 

33def to_float(s: str) -> Optional[float]: 

34 """ 

35 Convert a string to a float, or return ``None``. 

36 

37 Before converting: 

38 

39 - strips out commas (as thousands separator); this is not internationalized 

40 well! 

41 - replace Unicode minus and en dash with a hyphen (minus sign) 

42 """ 

43 if s: 

44 s = s.replace(",", "") # comma as thousands separator 

45 s = s.replace("−", "-") # Unicode minus 

46 s = s.replace("–", "-") # en dash 

47 try: 

48 return float(s) 

49 except (TypeError, ValueError): 

50 return None 

51 

52 

53def to_pos_float(s: str) -> Optional[float]: 

54 """ 

55 Converts a string to a positive float, by using :func:`to_float` followed 

56 by :func:`abs`. Returns ``None`` on failure. 

57 """ 

58 try: 

59 return abs(to_float(s)) 

60 except TypeError: # to_float() returned None 

61 return None