Add tools._pandas_to_utc

Author: yhkee0404

pvlib/clearsky.py

@@ -206,11 +206,7 @@ def lookup_linke_turbidity(time, latitude, longitude, filepath=None,
     with h5py.File(filepath, 'r') as lt_h5_file:
         lts = lt_h5_file['LinkeTurbidity'][latitude_index, longitude_index]
 
-    # if localized, convert to UTC. otherwise, assume UTC.
-    try:
-        time_utc = time.tz_convert('UTC')
-    except TypeError:
-        time_utc = time
+    time_utc = tools._pandas_to_utc(time)
 
     if interp_turbidity:
         linke_turbidity = _interpolate_turbidity(lts, time_utc)

pvlib/irradiance.py

@@ -126,13 +126,7 @@ def _handle_extra_radiation_types(datetime_or_doy, epoch_year):
     # a better way to do it.
     if isinstance(datetime_or_doy, pd.DatetimeIndex):
         to_doy = tools._pandas_to_doy  # won't be evaluated unless necessary
-        def to_datetimeindex(x):                                # noqa: E306
-            # if localized, convert to UTC. otherwise, assume UTC.
-            try:
-                x_utc = x.tz_convert('UTC')
-            except TypeError:
-                x_utc = x
-            return x_utc
+        to_datetimeindex = tools._pandas_to_utc
         to_output = partial(pd.Series, index=datetime_or_doy)
     elif isinstance(datetime_or_doy, pd.Timestamp):
         to_doy = tools._pandas_to_doy

pvlib/solarposition.py

@@ -24,7 +24,7 @@
 import warnings
 import datetime
 
-from pvlib import atmosphere
+from pvlib import atmosphere, tools
 from pvlib.tools import datetime_to_djd, djd_to_datetime
 
 
@@ -200,11 +200,7 @@ def spa_c(time, latitude, longitude, pressure=101325, altitude=0,
         raise ImportError('Could not import built-in SPA calculator. ' +
                           'You may need to recompile the SPA code.')
 
-    # if localized, convert to UTC. otherwise, assume UTC.
-    try:
-        time_utc = time.tz_convert('UTC')
-    except TypeError:
-        time_utc = time
+    time_utc = tools._pandas_to_utc(time)
 
     spa_out = []
 
@@ -645,11 +641,7 @@ def pyephem(time, latitude, longitude, altitude=0, pressure=101325,
     except ImportError:
         raise ImportError('PyEphem must be installed')
 
-    # if localized, convert to UTC. otherwise, assume UTC.
-    try:
-        time_utc = time.tz_convert('UTC')
-    except TypeError:
-        time_utc = time
+    time_utc = tools._pandas_to_utc(time)
 
     sun_coords = pd.DataFrame(index=time)
 
@@ -766,11 +758,7 @@ def ephemeris(time, latitude, longitude, pressure=101325, temperature=12):
     # the SPA algorithm needs time to be expressed in terms of
     # decimal UTC hours of the day of the year.
 
-    # if localized, convert to UTC. otherwise, assume UTC.
-    try:
-        time_utc = time.tz_convert('UTC')
-    except TypeError:
-        time_utc = time
+    time_utc = tools._pandas_to_utc(time)
 
     # strip out the day of the year and calculate the decimal hour
     DayOfYear = time_utc.dayofyear

pvlib/tools.py

@@ -207,12 +207,28 @@ def _pandas_to_doy(pd_object):
     -------
     dayofyear
     """
-    # if localized, convert to UTC. otherwise, assume UTC.
+    return _pandas_to_utc(pd_object).dayofyear
+
+
+def _pandas_to_utc(pd_object):
+    """
+    Converts a pandas datetime-like object to UTC, if localized.
+    Otherwise, assume UTC.
+
+    Parameters
+    ----------
+    pd_object : DatetimeIndex or Timestamp
+
+    Returns
+    -------
+    pandas object localized to or assumed to be UTC.
+    """
+    # 
     try:
         pd_object_utc = pd_object.tz_convert('UTC')
     except TypeError:
         pd_object_utc = pd_object
-    return pd_object_utc.dayofyear
+    return pd_object_utc
 
 
 def _doy_to_datetimeindex(doy, epoch_year=2014):
@@ -242,11 +258,7 @@ def _datetimelike_scalar_to_datetimeindex(time):
 
     timestamp = pd.Timestamp(time)
 
-    # if localized, convert to UTC. otherwise, assume UTC.
-    try:
-        timestamp_utc = timestamp.tz_convert('UTC')
-    except TypeError:
-        timestamp_utc = timestamp
+    timestamp_utc = _pandas_to_utc(timestamp)
 
     return pd.DatetimeIndex([timestamp_utc])