Use more variable type annotations compatible to 3.5

pyndl/count.py

@@ -67,7 +67,7 @@ def cues_outcomes(event_file_name: str,
                                 for start in range(number_of_processes)))
         n_events = 0
         cues = Counter()  # type: Counter
-        outcomes: Counter = Counter()
+        outcomes = Counter()  # type: Counter
         for nn, cues_process, outcomes_process in results:
             n_events += nn
             cues += cues_process

pyndl/ndl.py

@@ -301,7 +301,7 @@ class WeightDict(defaultdict):
     def __init__(self, *args, **kwargs) -> None:
         super().__init__(lambda: defaultdict(float))
 
-        self._attrs: OrderedDict = OrderedDict()
+        self._attrs = OrderedDict()  # type: OrderedDict
 
         if 'attrs' in kwargs:
             self.attrs = kwargs['attrs']

pyndl/preprocess.py

@@ -333,7 +333,7 @@ def process_context(line):
         with gzip.open(event_file, "wt") as outfile:
             outfile.write("cues\toutcomes\n")
 
-            words: List[str] = []
+            words = []  # type: List[str]
             for ii, line in enumerate(corpus):
                 if verbose and ii % 100000 == 0:
                     print(".", end="")

pyndl/types.py

@@ -1,9 +1,5 @@
-from typing import Dict, Iterator, Tuple, TypeVar
+from typing import Dict, Iterator, Tuple, TypeVar, Collection
 
-try:
-    from typing import Collection
-except ImportError:
-    from collections.abc import Collection
 
 from numpy import ndarray
 from xarray.core.dataarray import DataArray