Source Code for Module parser_course.small_parsers.var_printer

 1 -def debug_print (intro_string, Vars, Env, indent=3): 
 2      """ 
 3      Utility function for printing var values conveniently:: 
 4        -- C{intro_string}: arbitrary label of type string.  Will 
 5           be printed as prefix to the info below.  Usually the name 
 6           of the function calling C{debug_print}, but can be the 
 7           empty string. 
 8        __ C{Vars}:  A tuple of varnames, that is, a tuple of expressions 
 9           that evaluate to var names. 
10        -- C{Env}: A dictionary of variable name value pairs, usually 
11            by calling C{vars()}. 
12      For example:: 
13   
14         >>> var_printer.debug_print('scanner', ('goal_cat','index'),vars()) 
15   
16      prints:: 
17   
18         scanner 
19            goal_cat: np 
20            index   : 0 
21   
22      if the values of the variables C{goal_cat} and C{index} in 
23      environment C{vars()} are 'np' and '0' respectively.  Note 
24      the default indent of 3. 
25      """ 
26       
27      print '%s: ' % intro_string 
28      print_vars(Env, Vars, indent) 
29   
30 -def print_vars(Env, Vars=(), Indent=0): 
31      """C{Env} is a dictionary containing bindings 
32      for all the variables whose strings names are in the 
33      sequence of strings C{Vars} (which may be a singleton string 
34      as well). C{Env} is usually gotten by calling C{vars()}. 
35      So a typical call:: 
36   
37         >>> print_vars(vars(),('foo','foobar')) 
38         foo   : 'xxx' 
39         foobar: 'yyyyy' 
40   
41      If C{Vars} is empty, all the keys of Env are printed. 
42      """ 
43      if isinstance(Vars, str): 
44          Vars=(Vars,) 
45      elif not Vars: 
46          Vars = Env.keys() 
47      MinWidth=0 
48      for Var in Vars: 
49          if len(Var) > MinWidth: 
50              MinWidth=len(Var) 
51      for Var in Vars: 
52          # Varname printing left justified ('-') to 
53          # width of longest var (MinWidth, invoked by '*') 
54          # Var Value printed using 'repr'(output format 'r') 
55          pstr = '%-*s: %%(%s)r' % (MinWidth,Var,Var) 
56          print ' ' * Indent, 
57          try: 
58              print pstr % Env 
59          except KeyError, Key: 
60              raise NameError, "name '%s' is not defined" % Key 
61