1  """
 2  Utility Classes
 3  """
 4  
 5  import sys
 6  import collections
 7  import warnings
 8  
 9  from io import StringIO  # noqa: F401
10  
11  # galgebra 0.5.0
12  warnings.warn(
13      "galgebra.utils is deprecated and will be removed. "
14      "If you need python 2 compatibility helpers, use a decdicated module like "
15      "`six`.", DeprecationWarning, stacklevel=2)
16  
17  # From https://github.com/benjaminp/six/blob/master/six.py
18  PY2 = sys.version_info[0] == 2
19  PY3 = sys.version_info[0] == 3
20  
21  string_types = str
22  
23  # https://stackoverflow.com/questions/16176742/python-3-replacement-for-deprecated-compiler-ast-flatten-function
24  
25  
26  def flatten(x):
27      result = []
28  
29      for el in x:
30          if isinstance(x, collections.Iterable) and not isstr(el):
31              result.extend(flatten(el))
32          else:
33              result.append(el)
34      return result
35  
36  
37  def isstr(s):
38      return isinstance(s, str)