This function allows Python-style formatting of strings,
whereby text of the form {0}, {1}, ..., {n} is
substituted according to the matching argument passed to
.... 0 corresponds to the first argument,
1 corresponds to the second, and so on.
Usage
pymat(x, ..., collapse = ", ")
Arguments
x
A string with arguments to be replaced in the
form of {0}, {1}, ..., {n}.
...
Arguments to be substituted into x.
collapse
If vectors of length greater than 1 are
passed to ..., then we collapse the vectors with
this separator.