On Thu, Nov 7, 2019, at 22:19, yejus...@163.com wrote: > (1) Keeping the original syntax of List unchanged，for example： > a = [1,2,3] # will be parsed to a normal list. > b = [[1,2,3],[4,5,6]] # will be parsed to a normal list，too. > Simply put, all the original list syntax remains unchanged. > (2) Using semicolons as a flag to make a better integration of a > List-like data type and Numpy. The Python interpreter will check > whether the numpy library is installed. If not, it will stop running > and remind the user to install it. The expected syntax: > c = [1,2,3;] or c = [1 2 3;] or c = [1 2 3] > Notice the semicolon after the last number. If numpy is found, c > will be parsed as a Numpy ndarray. All these forms are equivelent to c > = np.array([1,2,3]). For a vector, the semicolon is the key for Python > to parse it as a Numpy ndarray. > > d=[1,2,3;4,5,6] or d=[1,2,3;4,5,6;] or d=[1 2 3;4 5 6] or d=[1 2 > 3;4 5 6;] > Notice the semicolons. If numpy is found, d will be parsed as a > Numpy ndarray. All these forms are equivelent to > d=np.array([[1,2,3],[4,5,6]]) > You see，for defining a matrix or a vector，it will be nearly as > simple as Matalab or Julia!
Possible alternate mechanisms: Make any such expression implicitly call a special function named e.g. __matrixhook__ - called by name, so a default in builtins and one could be set locally in a module or imported from numpy - or have the special function be installable in sys.matrixhook rather than based on a lexically scoped special name The default hook could: - raise an error suggesting to install numpy as in OP's suggestion - just build a list of lists These would require slightly more boilerplate (from numpy import __matrixhook__, or perhaps numpy could automatically initialize sys.matrixhook when loaded), but wouldn't favor a single non-stdlib library. _______________________________________________ Python-ideas mailing list -- python-ideas@python.org To unsubscribe send an email to python-ideas-le...@python.org https://mail.python.org/mailman3/lists/python-ideas.python.org/ Message archived at https://mail.python.org/archives/list/python-ideas@python.org/message/VEWHLESVE4M7EYW7REKW6FT5NEGLQRPI/ Code of Conduct: http://python.org/psf/codeofconduct/
