Move dimensionless_cycles to phase module

src/pint/phase.py

@@ -8,8 +8,6 @@
 from astropy.time.utils import two_sum, two_product
 from astropy.utils import minversion
 
-from pint import dimensionless_cycles
-
 
 __all__ = ['Phase', 'FractionalPhase']
 
@@ -22,6 +20,9 @@
     np.less, np.less_equal, np.greater, np.greater_equal}
 
 
+dimensionless_cycles = [(u.cycle, None)]
+
+
 def day_frac(val1, val2, factor=None, divisor=None):
     """Return the sum of ``val1`` and ``val2`` as two float64s.
 
@@ -170,6 +171,9 @@ def __new__(cls, angle, unit=None, wrap_angle=None, **kwargs):
         if isinstance(angle, Phase):
             angle = angle['frac']
 
+        if unit is None:
+            unit = cls._default_unit
+
         with u.add_enabled_equivalencies(dimensionless_cycles):
             return super().__new__(cls, angle, unit=unit, wrap_angle=wrap_angle,
                                    **kwargs)