Reorder hasattr() checks in mpf.mpf_convert_arg() and mp.convert()

Taken from sagemath/sage#38565 (comment)

Author: skirpichev

mpmath/ctx_mp_python.py

@@ -79,9 +79,6 @@ def mpf_convert_arg(cls, x, prec, rounding):
         if isinstance(x, int_types): return from_int(x)
         if isinstance(x, float): return from_float(x)
         if isinstance(x, cls.context.constant): return x.func(prec, rounding)
-        if isinstance(x, numbers.Rational): return from_rational(x.numerator,
-                                                                 x.denominator,
-                                                                 prec, rounding)
         if hasattr(x, '_mpf_'): return x._mpf_
         if hasattr(x, '_mpmath_'):
             t = cls.context.convert(x._mpmath_(prec, rounding))
@@ -92,6 +89,9 @@ def mpf_convert_arg(cls, x, prec, rounding):
             if a == b:
                 return a
             raise ValueError("can only create mpf from zero-width interval")
+        if isinstance(x, numbers.Rational): return from_rational(x.numerator,
+                                                                 x.denominator,
+                                                                 prec, rounding)
         if type(x).__module__ == 'decimal':
             return from_Decimal(x, prec, rounding)
         raise TypeError("cannot create mpf from " + repr(x))
@@ -724,6 +724,10 @@ def convert(ctx, x, strings=True):
             return ctx.make_mpc((from_float(x.real), from_float(x.imag)))
         if type(x).__module__ == 'numpy': return ctx.npconvert(x)
         prec, rounding = ctx._prec_rounding
+        if hasattr(x, '_mpf_'): return ctx.make_mpf(x._mpf_)
+        if hasattr(x, '_mpc_'): return ctx.make_mpc(x._mpc_)
+        if hasattr(x, '_mpmath_'):
+            return ctx.convert(x._mpmath_(prec, rounding))
         if isinstance(x, numbers.Rational):
             p, q = x.numerator, x.denominator
             return ctx.make_mpf(from_rational(p, q, prec, rounding))
@@ -733,10 +737,6 @@ def convert(ctx, x, strings=True):
                 return ctx.make_mpf(_mpf_)
             except ValueError:
                 pass
-        if hasattr(x, '_mpf_'): return ctx.make_mpf(x._mpf_)
-        if hasattr(x, '_mpc_'): return ctx.make_mpc(x._mpc_)
-        if hasattr(x, '_mpmath_'):
-            return ctx.convert(x._mpmath_(prec, rounding))
         if type(x).__module__ == 'decimal':
             return ctx.make_mpf(from_Decimal(x, prec, rounding))
         return ctx._convert_fallback(x, strings)