...concerning your editing comment for the page Tentative_NumPy_Tutorial:
"Because of the wiki editor, I think the only way to show C[:,1] is C[...,1]."
There are different solutions possible:
Display text as inline code: Markup `C[:,1]` gives C[:,1]
If you want standard text format use `` to break link-detection: Markup C[``:,1] gives: C[:,1]