How do I find the length or dimensions size of a numpy matrix in python

Question

For a numpy matrix in python  from numpy import matrix A   matrix   1 2   3 4      How can I find the length of a row  or column  of this matrix  Equivalently  how can I know the number of rows or columns   So far  the only solution I ve found is   len A  len A   1   len A 1       Which returns 2  2  and 1  respectively  From this I ve gathered that len   will return the number of rows  so I can always us the transpose  len A T   for the number of columns  However  this feels unsatisfying and arbitrary  as when reading the line len A   it isn t immediately obvious that this should return the number of rows  It actually works differently than len  1 2   would for a 2D python array  as this would return 2   So  is there a more intuitive way to find the size of a matrix  or is this the best I have

User · Accepted Answer

shape is a property of both numpy ndarray s and matrices   A shape   will return a tuple  m  n   where m is the number of rows  and n is the number of columns   In fact  the numpy matrix object is built on top of the ndarray object  one of numpy s two fundamental objects  along with a universal function object   so it inherits from ndarray

User · Answer

matrix size according to the numpy docs returns the Number of elements in the array  Hope that helps

[python] How do I find the length (or dimensions, size) of a numpy matrix in python?

Examples related to python

Examples related to matrix

Examples related to numpy