use application reg in docs

docs/advanced/defining.rst

@@ -53,18 +53,19 @@ way is to create a new file (e.g. `mydef.txt`) with your definitions::
 
 and then in Python, you can load it as:
 
-   >>> from pint import UnitRegistry
+   >>> import pint
    >>> # First we create the registry.
-   >>> ureg = UnitRegistry()
+   >>> ureg = pint.UnitRegistry()
+   >>> # Set pint to use the new registry
+   >>> pint.set_application_registry(ureg)
    >>> # Then we append the new definitions
    >>> ureg.load_definitions('/your/path/to/my_def.txt') # doctest: +SKIP
 
 If you make a translation of the default units or define a completely new set,
 you don't want to append the translated definitions so you just give the
 filename to the constructor::
 
-   >>> from pint import UnitRegistry
-   >>> ureg = UnitRegistry('/your/path/to/default_es.txt') # doctest: +SKIP
+   >>> ureg = pint.UnitRegistry('/your/path/to/default_es.txt') # doctest: +SKIP
 
 In the definition file, prefixes are identified by a trailing dash::
 
@@ -100,10 +101,11 @@ Let's add a dog_year (sometimes written as dy) equivalent to 52 (human) days:
 
 .. doctest::
 
-   >>> from pint import UnitRegistry
+   >>> import pint
    >>> # We first instantiate the registry.
    >>> # If we do not provide any parameter, the default unit definitions are used.
-   >>> ureg = UnitRegistry()
+   >>> ureg = pint.UnitRegistry()
+   >>> pint.set_application_registry(ureg)
    >>> Q_ = ureg.Quantity
 
    # Here we add the unit

docs/advanced/measurement.rst

@@ -16,8 +16,9 @@ quantity using the ``plus_minus()`` method.
    :skipif: not_installed['uncertainties']
 
    >>> import numpy as np
-   >>> from pint import UnitRegistry
-   >>> ureg = UnitRegistry()
+   >>> import pint
+   >>> ureg = pint.UnitRegistry()
+   >>> ureg = pint.get_application_registry()
    >>> book_length = (20. * ureg.centimeter).plus_minus(2.)
    >>> print(book_length)
    (20.0 +/- 2.0) centimeter

docs/advanced/performance.rst

@@ -16,9 +16,9 @@ It's significantly faster to perform mathematical operations on magnitudes (even
 .. ipython::
     :verbatim:
 
-    In [1]: from pint import UnitRegistry
+    In [1]: import pint
 
-    In [2]: ureg = UnitRegistry()
+    In [2]: ureg = pint.get_application_registry()
 
     In [3]: q1 = ureg('1m')
 
@@ -69,7 +69,7 @@ A better way to use magnitudes is to use pint's wraps decorator (See :ref:`wrapp
 
     In [1]: import pint
 
-    In [2]: ureg = pint.UnitRegistry()
+    In [2]: ureg = pint.get_application_registry()
 
     In [3]: import numpy as np
 

docs/advanced/pitheorem.rst

@@ -10,8 +10,8 @@ parameters.
 
 .. testsetup:: *
 
-   from pint import UnitRegistry
-   ureg = UnitRegistry()
+   import pint
+   ureg = pint.UnitRegistry()
    Q_ = ureg.Quantity
 
 To start with a very simple case, consider that you want to find a dimensionless
@@ -41,8 +41,8 @@ you can use derived dimensions such as speed:
 
 .. doctest::
 
-    >>> from pint import UnitRegistry
-    >>> ureg = UnitRegistry()
+    >>> import pint
+    >>> ureg = pint.UnitRegistry()
     >>> ureg.pi_theorem({'V': '[speed]', 'T': '[time]', 'L': '[length]'})
     [{'V': 1.0, 'T': 1.0, 'L': -1.0}]
 

docs/advanced/serialization.rst

@@ -11,7 +11,7 @@ The easiest way to do this is by converting the quantity to a string:
 .. doctest::
 
    >>> import pint
-   >>> ureg = pint.UnitRegistry()
+   >>> ureg = pint.get_application_registry()
    >>> duration = 24.2 * ureg.years
    >>> duration
    <Quantity(24.2, 'year')>
@@ -28,7 +28,7 @@ to recover it in another process/machine, you just:
 .. doctest::
 
    >>> import pint
-   >>> ureg = pint.UnitRegistry()
+   >>> ureg = pint.get_application_registry()
    >>> duration = ureg('24.2 year')
    >>> print(duration)
    24.2 year

docs/advanced/wrapping.rst

@@ -45,8 +45,8 @@ You could wrap this function to use Quantities instead:
 
 .. doctest::
 
-    >>> from pint import UnitRegistry
-    >>> ureg = UnitRegistry()
+    >>> import pint
+    >>> ureg = pint.get_application_registry()
     >>> Q_ = ureg.Quantity
     >>> def mypp_caveman(length):
     ...     return pendulum_period(length.to(ureg.meter).magnitude) * ureg.second

docs/getting/overview.rst

@@ -22,7 +22,7 @@ It is extremely easy and natural to use:
 .. code-block:: python
 
     >>> import pint
-    >>> ureg = pint.UnitRegistry()
+    >>> ureg = pint.get_application_registry()
     >>> 3 * ureg.meter + 4 * ureg.cm
     <Quantity(3.04, 'meter')>
 

docs/getting/tutorial.rst

@@ -8,17 +8,15 @@ and perform unit conversions in Python.
 Initializing a Registry
 -----------------------
 
-Before using Pint, initialize a :class:`UnitRegistry() <pint.registry.UnitRegistry>`
-object. The ``UnitRegistry`` stores the unit definitions, their relationships,
-and handles conversions between units.
+Pint's ``UnitRegistry`` stores the unit definitions, their relationships,
+and handles conversions between units. A ``UnitRegistry`` populated with the
+`default list of units`_ and prefixes is initialized when you import Pint:
 
 .. doctest::
 
-   >>> from pint import UnitRegistry
-   >>> ureg = UnitRegistry()
+   >>> import pint
+   >>> ureg = pint.get_application_registry()
 
-If no parameters are given to the constructor, the ``UnitRegistry`` is populated
-with the `default list of units`_ and prefixes.
 
 Defining a Quantity
 -------------------
@@ -434,7 +432,8 @@ You can also specify the format locale at the registry level either at creation:
 
 .. doctest::
 
-    >>> ureg = UnitRegistry(fmt_locale='fr_FR')
+    >>> ureg = pint.UnitRegistry(fmt_locale='fr_FR')
+    >>> pint.set_application_registry(ureg)
 
 or later:
 

docs/user/angular_frequency.rst

@@ -10,8 +10,8 @@ By default, pint treats angle quantities as `dimensionless`, so allows conversio
 
 .. code-block:: python
 
-    >> from pint import UnitRegistry
-    >>> ureg = UnitRegistry()
+    >>> import pint
+    >>> ureg = pint.get_application_registry()
     >>> angular_frequency = ureg('60rpm')
     >>> angular_frequency.to('Hz')
     <Quantity(6.28318531, 'hertz')>

docs/user/contexts.rst

@@ -11,7 +11,7 @@ raise an error if you do this directly:
 .. doctest::
 
     >>> import pint
-    >>> ureg = pint.UnitRegistry()
+    >>> ureg = pint.get_application_registry()
     >>> q = 500 * ureg.nm
     >>> q.to('Hz')
     Traceback (most recent call last):
@@ -198,6 +198,7 @@ functions. For example:
 .. doctest::
 
     >>> ureg = pint.UnitRegistry()
+    >>> pint.set_application_registry(ureg)
     >>> c = pint.Context('ab')
     >>> c.add_transformation('[length]', '[time]',
     ...                      lambda ureg, x: x / ureg.speed_of_light)
@@ -258,7 +259,7 @@ Programmatically:
 
 .. code-block:: python
 
-    >>> ureg = pint.UnitRegistry()
+    >>> ureg = pint.get_application_registry()
     >>> q = ureg.Quantity("1 BTU")
     >>> q.to("J")
     1055.056 joule
@@ -278,7 +279,7 @@ Or with a definitions file::
 
 .. code-block:: python
 
-    >>> ureg = pint.UnitRegistry()
+    >>> ureg = pint.get_application_registry()
     >>> ureg.load_definitions("somefile.txt")
     >>> q = ureg.Quantity("1 BTU")
     >>> q.to("J")

docs/user/defining-quantities.rst

@@ -16,8 +16,9 @@ quantity by multiplying a ``Unit()`` and a scalar:
 
 .. doctest::
 
-    >>> from pint import UnitRegistry
-    >>> ureg = UnitRegistry()
+    >>> import pint
+    >>> ureg = pint.UnitRegistry()
+    >>> pint.set_application_registry(ureg)
     >>> ureg.meter
     <Unit('meter')>
     >>> 30.0 * ureg.meter

docs/user/formatting.rst

@@ -17,7 +17,7 @@ where each part is optional and the order of these is arbitrary.
 .. doctest::
 
    >>> import pint
-   >>> ureg = pint.UnitRegistry()
+   >>> ureg = pint.get_application_registry()
    >>> q = 2.3e-6 * ureg.m ** 3 / (ureg.s ** 2 * ureg.kg)
    >>> f"{q:~P}"  # short pretty
    '2.3×10⁻⁶ m³/kg/s²'
@@ -67,6 +67,7 @@ Modifier Meaning                                             Example
 ``#``    Call :py:meth:`Quantity.to_compact` first           ``1.0 m·mg/s²`` (``f"{q:#~P}"``)
 ======== =================================================== ================================
 
+
 Unit modifiers
 --------------
 

docs/user/nonmult.rst

@@ -16,8 +16,9 @@ For example, to convert from celsius to fahrenheit:
 
 .. doctest::
 
-    >>> from pint import UnitRegistry
-    >>> ureg = UnitRegistry()
+    >>> import pint
+    >>> ureg = pint.UnitRegistry()
+    >>> pint.set_application_registry(ureg)
     >>> ureg.default_format = '.3f'
     >>> Q_ = ureg.Quantity
     >>> home = Q_(25.4, ureg.degC)
@@ -113,7 +114,8 @@ to be explicitly created:
 
 .. doctest::
 
-    >>> ureg = UnitRegistry()
+    >>> ureg = pint.UnitRegistry()
+    >>> pint.set_application_registry(ureg)
     >>> home = 25.4 * ureg.degC
     Traceback (most recent call last):
         ...
@@ -130,7 +132,8 @@ to true. In this mode, pint behaves differently:
 
 .. doctest::
 
-    >>> ureg = UnitRegistry(autoconvert_offset_to_baseunit = True)
+    >>> ureg = pint.UnitRegistry(autoconvert_offset_to_baseunit = True)
+    >>> pint.set_application_registry(ureg)
     >>> T = 25.4 * ureg.degC
     >>> T
     <Quantity(25.4, 'degree_Celsius')>

docs/user/numpy.ipynb

@@ -38,7 +38,7 @@
     "# Import Pint\n",
     "import pint\n",
     "\n",
-    "ureg = pint.UnitRegistry()\n",
+    "ureg = pint.get_application_registry()\n",
     "Q_ = ureg.Quantity\n",
     "\n",
     "# Silence NEP 18 warning\n",

docs/user/plotting.rst

@@ -13,12 +13,12 @@ a **UnitRegistry**:
 .. testsetup:: *
 
    import pint
-   ureg = pint.UnitRegistry()
+   ureg = pint.get_application_registry()
 
 .. doctest::
 
    >>> import pint
-   >>> ureg = pint.UnitRegistry()
+   >>> ureg = pint.get_application_registry()
    >>> ureg.setup_matplotlib()
 
 This support can also be disabled with:
@@ -36,7 +36,7 @@ This allows plotting quantities with different units:
    import numpy as np
    import pint
 
-   ureg = pint.UnitRegistry()
+   ureg = pint.get_application_registry()
    ureg.setup_matplotlib(True)
 
    y = np.linspace(0, 30) * ureg.miles
@@ -56,7 +56,7 @@ This also allows controlling the actual plotting units for the x and y axes:
    import numpy as np
    import pint
 
-   ureg = pint.UnitRegistry()
+   ureg = pint.get_application_registry()
    ureg.setup_matplotlib(True)
 
    y = np.linspace(0, 30) * ureg.miles
@@ -79,7 +79,7 @@ Users have the possibility to change the format of the units on the plot:
    import numpy as np
    import pint
 
-   ureg = pint.UnitRegistry()
+   ureg = pint.get_application_registry()
    ureg.setup_matplotlib(True)
 
    ureg.mpl_formatter = "{:~P}"

docs/user/systems.rst

@@ -9,6 +9,7 @@ Pint Unit Registry has the concept of system, which is a group of units
 
     >>> import pint
     >>> ureg = pint.UnitRegistry(system='mks')
+    >>> pint.set_application_registry(ureg)
     >>> ureg.default_system
     'mks'