Class Timer

Lib/timeit.py:87–239

Class for timing execution speed of small code snippets. The constructor takes a statement to be timed, an additional statement used for setup, and a timer function. Both statements default to 'pass'; the timer function is platform-dependent (see module doc string). If 'globals' i

class Timer:
    """Class for timing execution speed of small code snippets.

    The constructor takes a statement to be timed, an additional
    statement used for setup, and a timer function.  Both statements
    default to 'pass'; the timer function is platform-dependent (see
    module doc string).  If 'globals' is specified, the code will be
    executed within that namespace (as opposed to inside timeit's
    namespace).

    To measure the execution time of the first statement, use the
    timeit() method.  The repeat() method is a convenience to call
    timeit() multiple times and return a list of results.

    The statements may contain newlines, as long as they don't contain
    multi-line string literals.
    """

    def __init__(self, stmt="pass", setup="pass", timer=default_timer,
                 globals=None):
        """Constructor.  See class doc string."""
        self.timer = timer
        local_ns = {}
        global_ns = _globals() if globals is None else globals
        init = ''
        if isinstance(setup, str):
            # Check that the code can be compiled outside a function
            compile(setup, dummy_src_name, "exec")
            stmtprefix = setup + '\n'
            setup = reindent(setup, 4)
        elif callable(setup):
            local_ns['_setup'] = setup
            init += ', _setup=_setup'
            stmtprefix = ''
            setup = '_setup()'
        else:
            raise ValueError("setup is neither a string nor callable")
        if isinstance(stmt, str):
            # Check that the code can be compiled outside a function
            compile(stmtprefix + stmt, dummy_src_name, "exec")
            stmt = reindent(stmt, 8)
        elif callable(stmt):
            local_ns['_stmt'] = stmt
            init += ', _stmt=_stmt'
            stmt = '_stmt()'
        else:
            raise ValueError("stmt is neither a string nor callable")
        src = template.format(stmt=stmt, setup=setup, init=init)
        self.src = src  # Save for traceback display
        code = compile(src, dummy_src_name, "exec")
        exec(code, global_ns, local_ns)
        self.inner = local_ns["inner"]

    def print_exc(self, file=None, **kwargs):
        """Helper to print a traceback from the timed code.

        Typical use: