Replaced some more formatted strings...

to work around the numba issue described here: numba/numba#3250

climate_indices/eto.py

@@ -88,10 +88,8 @@ def _sunset_hour_angle(latitude_radians, solar_declination_radians):
     # http://www.itacanet.org/the-sun-as-a-source-of-energy/part-1-solar-astronomy/
     if (not _SOLAR_DECLINATION_RADIANS_MIN
             <= solar_declination_radians <= _SOLAR_DECLINATION_RADIANS_MAX):
-        raise ValueError("solar declination angle outside "
-                         f"valid range [{_SOLAR_DECLINATION_RADIANS_MIN!r} "
-                         f"to {_SOLAR_DECLINATION_RADIANS_MAX!r}]: "
-                         f"{solar_declination_radians!r}")
+        raise ValueError("solar declination angle outside valid range [{_SOLAR_DECLINATION_RADIANS_MIN!r} to {_SOLAR_DECLINATION_RADIANS_MAX!r}]:{solar_declination_radians!r}".format(
+                             _SOLAR_DECLINATION_RADIANS_MIN, _SOLAR_DECLINATION_RADIANS_MAX, solar_declination_radians))
 
     # calculate the cosine of the sunset hour angle (*Ws* in FAO 25)
     # from latitude and solar declination
@@ -144,8 +142,7 @@ def _daylight_hours(sunset_hour_angle_radians):
     # range of 0 to pi radians (180 degrees), inclusive
     # see http://mypages.iit.edu/~maslanka/SolarGeo.pdf
     if not 0.0 <= sunset_hour_angle_radians <= math.pi:
-        raise ValueError(f"sunset hour angle outside valid range [0.0 to {math.pi!r}]"
-                         f": {sunset_hour_angle_radians!r}")
+        raise ValueError("sunset hour angle outside valid range [0.0 to {math.pi!r}]: {sunset_hour_angle_radians!r}".format(sunset_hour_angle_radians))
 
     # calculate daylight hours from the sunset hour angle
     return (24.0 / math.pi) * sunset_hour_angle_radians