fix(loading mflist from file) (#1179)

@aleaf @jtwhite79 has addressed this issue. See modified test (`t004_test_utilarray.py`) for an example of using external files for list data. Reopen if this does not solve your issue.

Closes #1073

autotest/t004_test_utilarray.py

@@ -889,9 +889,30 @@ def test_util3d_reset():
     ml.bas6.strt = arr
 
 
+def test_mflist_fromfile():
+    """test that when a file is passed to stress period data,
+    the .array attribute will load the file
+    """
+    import pandas as pd
+    import flopy
+
+    wel_data = pd.DataFrame([(0,1,2, -50.0),(0,5,5, -50.0)],
+                 columns=['k', 'i', 'j', 'flux'])
+    wel_data.to_csv('wel_000.dat', index=False, sep=' ',header=False)
+
+    nwt_model = flopy.modflow.Modflow('nwt_testmodel',verbose=True)
+    dis = flopy.modflow.ModflowDis(nwt_model, nlay=1, nrow=10, ncol=10, delr=500.0,
+                        delc=500.0, top=100.0, botm=50.0)
+    wel = flopy.modflow.ModflowWel(nwt_model, stress_period_data={0: 'wel_000.dat'})
+    flx_array = wel.stress_period_data.array["flux"][0]
+    for k,i,j,flx in zip(wel_data.k,wel_data.i,wel_data.j,wel_data.flux):
+        assert flx_array[k,i,j] == flx
+
+
 if __name__ == "__main__":
     # test_util3d_reset()
-    test_mflist()
+    #test_mflist()
+    test_mflist_fromfile()
     # test_new_get_file_entry()
     # test_arrayformat()
     # test_util2d_external_free_nomodelws()

flopy/utils/util_list.py

@@ -1086,6 +1086,8 @@ def to_array(self, kper=0, mask=False):
                 kper = self.__find_last_kper(kper)
 
         sarr = self.data[kper]
+        if isinstance(sarr, str):
+            sarr = self.__fromfile(sarr)
 
         if np.isscalar(sarr):
             # if there are no entries for this kper