Checking numerical value of a Theano expression

theano_chk_expr.py

import inspect # for line number
import re # for extracting debug information

_check_expr_regex = re.compile('THEANO_CHECK_EXPR\(.+\)')

def THEANO_CHECK_EXPR( expr, verbose = False ):
    """
    Check the expression
    Limited resolution at the line level
    """
    caller = inspect.currentframe().f_back
    try:
        caller_expr = inspect.stack()[1][4][0]
        caller_expr = ', '.join(_check_expr_regex.findall( caller_expr ))
    except:
        caller_expr = "NA"; pass

    caller_lineno = caller.f_back.f_lineno
    def_lineno = caller.f_lineno
    expr_str = theano.printing.debugprint( expr, depth = 1, print_type = False, ids = "", file = 'str' )
    print_prefix = 'DEBUG: [CALLER Ln %d, DEF Ln %d], { %s }' % ( caller_lineno, def_lineno, caller_expr.strip() )
    if verbose:
        print_prefix += ', ' + expr_str.strip()
    return theano.printing.Print( print_prefix + ":" )( expr )