Fix so that #55 works for both Python 2 and Python 3

psrqpy/__init__.py

@@ -7,7 +7,7 @@
 from .pulsar import Pulsar, Pulsars
 from .utils import *
 
-__version__ = "1.0.2"
+__version__ = "1.0.3"
 
 __citation__ = """@article{psrqpy,
   author = {{Pitkin}, M.},

psrqpy/search.py

@@ -15,10 +15,12 @@
 from six import string_types
 
 import numpy as np
-from astropy.coordinates import SkyCoord, ICRS, BarycentricMeanEcliptic, Galactic
+import astropy
+from astropy.coordinates import SkyCoord, ICRS, Galactic
 import astropy.units as aunits
 from astropy.constants import c, GM_sun
 from astropy.table import Table
+import packaging import version
 
 from pandas import DataFrame, Series
 from copy import deepcopy
@@ -27,6 +29,15 @@
 from .utils import condition, age_pdot, B_field_pdot
 
 
+# check whether to use BarycentricTrueEcliptic of BarycentricMeanEcliptic
+if packaging.version.parse(astropy.__version__) < packaging.version.parse("3.2"):
+    from astropy.coordinates import BarycentricMeanEcliptic
+    ASTROPY_V32 = True
+else:
+    from astropy.coordinates import BarycentricTrueEcliptic as BarycentricMeanEcliptic
+    ASTROPY_V32 = False
+
+
 class QueryATNF(object):
     """
     A class to generate a query of the
@@ -1316,8 +1327,12 @@ def derived_ecliptic(self):
         sc = SkyCoord(RAJD[idx].values*aunits.deg,
                       DECJD[idx].values*aunits.deg)
 
-        ELONGnew[idx] = sc.barycentricmeanecliptic.lon.value
-        ELATnew[idx] = sc.barycentricmeanecliptic.lat.value
+        if ASTROPY_V32:
+            ELONGnew[idx] = sc.barycentricmeanecliptic.lon.value
+            ELATnew[idx] = sc.barycentricmeanecliptic.lat.value
+        else:
+            ELONGnew[idx] = sc.barycentrictrueecliptic.lon.value
+            ELATnew[idx] = sc.barycentrictrueecliptic.lat.value
 
         self.update(ELONGnew, name='ELONG')
         self.update(ELATnew, name='ELAT')

requirements.txt

@@ -5,4 +5,5 @@ numpy
 scipy
 pandas>0.21
 astropy>=2.0,<3.0; python_version <= '2.7'
-astropy>=2.0; python_version > '3.4'
+astropy>=3.2; python_version > '3.4'
+packaging