.. This document was generated by tools/gen-cpydiff.py

Syntax
======
Generated Sun 16 Jan 2022 23:50:22 UTC

Operators
---------

.. _cpydiff_syntax_assign_expr:

MicroPython allows using := to assign to the variable of a comprehension, CPython raises a SyntaxError.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

**Cause:** MicroPython is optimised for code size and doesn't check this case.

**Workaround:** Do not rely on this behaviour if writing CPython compatible code.

Sample code::

    print([i := -1 for i in range(4)])

+-------------------------------------------------------------------------------------------+----------------------+
| CPy output:                                                                               | uPy output:          |
+-------------------------------------------------------------------------------------------+----------------------+
| ::                                                                                        | ::                   |
|                                                                                           |                      |
|       File "<stdin>", line 7                                                              |     [-1, -1, -1, -1] |
|     SyntaxError: assignment expression cannot rebind comprehension iteration variable 'i' |                      |
+-------------------------------------------------------------------------------------------+----------------------+

Spaces
------

.. _cpydiff_syntax_spaces:

uPy requires spaces between literal numbers and keywords, CPy doesn't
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Sample code::

    try:
        print(eval("1and 0"))
    except SyntaxError:
        print("Should have worked")
    try:
        print(eval("1or 0"))
    except SyntaxError:
        print("Should have worked")
    try:
        print(eval("1if 1else 0"))
    except SyntaxError:
        print("Should have worked")

+-------------+------------------------+
| CPy output: | uPy output:            |
+-------------+------------------------+
| ::          | ::                     |
|             |                        |
|     0       |     Should have worked |
|     1       |     Should have worked |
|     1       |     Should have worked |
+-------------+------------------------+

Unicode
-------

.. _cpydiff_syntax_unicode_nameesc:

Unicode name escapes are not implemented
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Sample code::

    print("\N{LATIN SMALL LETTER A}")

+-------------+-----------------------------------------------+
| CPy output: | uPy output:                                   |
+-------------+-----------------------------------------------+
| ::          | ::                                            |
|             |                                               |
|     a       |     NotImplementedError: unicode name escapes |
+-------------+-----------------------------------------------+