Make filter work for np 64 format years/dates (#370)

* Tests and code added

* Added documentation

* Appease stickler

* Fixing for review comments

Co-authored-by: Lamboll <rlamboll@ic.ac.uk>

RELEASE_NOTES.md

@@ -1,7 +1,7 @@
 # Next Release
 
 ## Individual Updates
-
+- [#370](https://github.com/IAMconsortium/pyam/pull/370) Allowed filter to work with np.int64 years and np.datetime64 dates.  
 - [#361](https://github.com/IAMconsortium/pyam/pull/361) iam-units refactored from a Git submodule to a Python dependency of pyam.
 
 # Release v0.5.0

pyam/core.py

@@ -1178,10 +1178,10 @@ def filter(self, keep=True, inplace=False, **kwargs):
                string or list of strings, where `*` can be used as a wildcard
              - 'level': the maximum "depth" of IAM variables (number of '|')
                (excluding the strings given in the 'variable' argument)
-             - 'year': takes an integer, a list of integers or a range
-               note that the last year of a range is not included,
+             - 'year': takes an integer (int/np.int64), a list of integers or
+                a range. Note that the last year of a range is not included,
                so `range(2010, 2015)` is interpreted as `[2010, ..., 2014]`
-             - arguments for filtering by `datetime.datetime`
+             - arguments for filtering by `datetime.datetime` or np.datetime64
                ('month', 'hour', 'time')
              - 'regexp=True' disables pseudo-regexp syntax in `pattern_match()`
         """

pyam/utils.py

@@ -353,8 +353,10 @@ def _escape_regexp(s):
 
 def years_match(data, years):
     """Return rows where data matches year"""
-    years = [years] if isinstance(years, int) else years
-    dt = datetime.datetime
+    years = [years] if (
+        isinstance(years, (int, np.int64))
+    ) else years
+    dt = (datetime.datetime, np.datetime64)
     if isinstance(years, dt) or isinstance(years[0], dt):
         error_msg = "`year` can only be filtered with ints or lists of ints"
         raise TypeError(error_msg)
@@ -423,9 +425,11 @@ def conv_strs(strs_to_convert, conv_codes, name):
 def datetime_match(data, dts):
     """Matching of datetimes in time columns for data filtering"""
     dts = dts if islistable(dts) else [dts]
-    if any([not isinstance(i, datetime.datetime) for i in dts]):
+    if any([not (
+            isinstance(i, (datetime.datetime, np.datetime64))
+    ) for i in dts]):
         error_msg = (
-            "`time` can only be filtered by datetimes"
+            "`time` can only be filtered by datetimes and datetime64s"
         )
         raise TypeError(error_msg)
     return data.isin(dts)

tests/test_core.py

@@ -317,6 +317,15 @@ def test_filter_day(test_df, test_day):
         assert unique_time[0] == expected
 
 
+def test_filter_with_numpy_64_date_vals(test_df):
+    dates = test_df[test_df.time_col].unique()
+    key = 'year' if test_df.time_col == "year" else 'time'
+    res_0 = test_df.filter(**{key: dates[0]})
+    res = test_df.filter(**{key: dates})
+    assert np.equal(res_0.data[res_0.time_col].values, dates[0]).all()
+    assert res.equals(test_df)
+
+
 @pytest.mark.parametrize("test_hour", [0, 12, [12, 13]])
 def test_filter_hour(test_df, test_hour):
     if "year" in test_df.data.columns: