fix optional dependencies

ejplugins/__init__.py

@@ -4,13 +4,14 @@
                                ECH3CubePlugin, ECH3OutPlugin)
 from ejplugins.qespresso import (QEmainPlugin, QEbandPlugin, QEChargeDensityPlugin,
                                  QELowdinPlugin, QEnscfPlugin, QEdosPlugin)
-from ejplugins.cif import CIFPlugin
 from ejplugins.gulp import GULPOutPlugin
 from ejplugins.lammps import LAMMPSAtomDumpPlugin, LAMMPSSysDumpPlugin
 
+# optional dependencies
 try:
     from ejplugins.pymatgen_decode import Encode_Pymatgen
     from ejplugins.ase_decode import Encode_ASE
+    from ejplugins.cif import CIFPlugin
 except ImportError:
     pass
 
@@ -28,9 +29,13 @@ def load_all_parsers():
     parsers = [CrystalOutputPlugin, CrystalSCFLogPlugin, CrystalDOSPlugin,
                BANDPlugin, ECH3CubePlugin, ECH3OutPlugin,
                QEmainPlugin, QEbandPlugin, QEChargeDensityPlugin, QELowdinPlugin,
-               CIFPlugin,
                GULPOutPlugin,
                LAMMPSAtomDumpPlugin, LAMMPSSysDumpPlugin]
+    try:
+        from ejplugins.cif import CIFPlugin
+        parsers.append(CIFPlugin)
+    except ImportError:
+        pass
 
     return plugins.load_plugin_classes(parsers, "parsers")
 

ejplugins/qespresso.py

@@ -14,7 +14,6 @@
 from fnmatch import fnmatch
 
 import numpy as np
-from ase import Atoms
 from ejplugins.utils import codata, split_numbers, symbol2anum
 from jsonextended import edict
 
@@ -886,6 +885,7 @@ class QEChargeDensityPlugin(object):
     file_regex = '*.qe.charge'
 
     def read_file(self, f, **kwargs):
+        from ase import Atoms  # optional dependency
         comment = f.readline().strip()  # first line blank
         line = f.readline().strip()
         try:

requirements.txt

@@ -1,3 +1,4 @@
 jsonextended>=0.6.4
 pathlib2
-jsonschema
+jsonschema
+pint

setup.py

@@ -24,9 +24,8 @@
         extras_require={
             "science": [
                 "pymatgen",
-                "ase",
-                "pint"
-            ]
+                "ase"
+                ]
         },
         license='MIT',
         author='Chris Sewell',