Source Code for Module pyraf.describe

  1  # http://www.dejanews.com/getdoc.xp?AN=382948703 
  2  # 
  3  # Instant Python 
  4  # $Id: describe.py 678 2005-07-01 21:19:43Z perry $ 
  5  # 
  6  # utilities to describe functions, methods, and classes 
  7  # 
  8  # history: 
  9  # 96-10-27 fl     created 
 10  # 98-02-24 fl     added code to handle unpacked arguments 
 11  # 01-11-13 rlw    added UNPACK_SEQUENCE to UNPACK_TUPLE for tuple args 
 12  #                 (Changed for Python2.0) 
 13  # 
 14  # notes: 
 15  # This has been tested with Python 1.4 and 1.5.  The code and 
 16  # function object attributes might change in future versions of 
 17  # Python. 
 18  # 
 19  # written by fredrik lundh.  last updated february 1998. 
 20  # 
 21  # fredrik@pythonware.com 
 22  # http://www.pythonware.com 
 23  # 
 24   
 25  import string 
 26  from dis import opname, HAVE_ARGUMENT 
 27   
 28  # -------------------------------------------------------------------- 
 29  # code object attributes 
 30  # -------------------------------------------------------------------- 
 31  # co_argcount   INT 
 32  # co_nlocals    INT 
 33  # co_flags      INT 
 34  #       CO_OPTIMIZED 
 35  #       CO_NEWLOCALS 
 36  #       CO_VARARGS 
 37  #       CO_VARKEYWORDS 
 38  # co_code       OBJECT 
 39  # co_consts     OBJECT 
 40  # co_names      OBJECT 
 41  # co_varnames   OBJECT 
 42  # co_filename   OBJECT 
 43  # co_name       OBJECT 
 44   
 45  # -------------------------------------------------------------------- 
 46  # function object attributes 
 47  # -------------------------------------------------------------------- 
 48  # func_code     OBJECT 
 49  # func_globals  OBJECT 
 50  # func_name     OBJECT (__name__) 
 51  # func_defaults OBJECT 
 52  # func_doc      OBJECT (__doc__) 
 53   
 54  # copied from Python header file 
 55  CO_OPTIMIZED = 0x0001 
 56  CO_NEWLOCALS = 0x0002 
 57  CO_VARARGS = 0x0004 
 58  CO_VARKEYWORDS = 0x0008 
 59   
 60 -def describeParams(func, name = None): 
 61      # get argument list 
 62   
 63      code = func.func_code 
 64   
 65      n = code.co_argcount 
 66      a = list(code.co_varnames[:n]) 
 67      p = 0 
 68      for i in range(n): 
 69          # anonymous arguments 
 70          c = code.co_code 
 71          if not a[i] or a[i][0] == ".": 
 72              vars = [] 
 73              while p < len(c): 
 74                  v = ord(c[p]) 
 75                  if v >= HAVE_ARGUMENT: 
 76                      s, v = opname[v], ord(c[p+1]) + ord(c[p+2])*256 
 77                      p = p + 3 
 78                      if s in ("UNPACK_SEQUENCE", "UNPACK_TUPLE"): 
 79                          count = v 
 80                      elif s == "STORE_FAST": 
 81                          vars.append(code.co_varnames[v]) 
 82                          if len(vars) >= count: 
 83                              break 
 84                  else: 
 85                      p = p + 1 
 86              if vars: 
 87                  a[i] = "(" + string.join(vars, ", ") + ")" 
 88      if func.func_defaults: 
 89          # defaults 
 90          i = n - len(func.func_defaults) 
 91          for d in func.func_defaults: 
 92              a[i] = (a[i], d) 
 93              i = i + 1 
 94      if code.co_flags & CO_VARARGS: 
 95          # extra arguments 
 96          a.append("*"+code.co_varnames[n]) 
 97          n = n + 1 
 98      if code.co_flags & CO_VARKEYWORDS: 
 99          # extra keyword arguments 
100          a.append("**"+code.co_varnames[n]) 
101          n = n + 1 
102      return a 
103   
104 -def describe(func, name = None): 
105      "Return the function or method declaration as a string" 
106   
107      # argument list 
108      a = describeParams(func) 
109      args = [] 
110      for arg in a: 
111          if type(arg) == type(""): 
112              args.append(arg) 
113          else: 
114              args.append("%s=%s" % (arg[0], repr(arg[1]))) 
115      args = string.join(args, ", ") 
116   
117      # function name 
118      if not name: 
119          # func_name is considered obsolete, use __name__ instead 
120          # name = func.func_name 
121          name = func.__name__ 
122          if name == "<lambda>": 
123              return "lambda %s" % args 
124      return "%s(%s)" % (name, args) 
125   
126 -def __getmethods(c, m): 
127      for k, v in c.__dict__.items(): 
128          if type(v) == type(__getmethods): # and k[0] != "_": 
129              if not m.has_key(k): 
130                  m[k] = describe(v, k), c.__name__ 
131      for c in c.__bases__: 
132          __getmethods(c, m) 
133   
134 -def describe_class(cls): 
135      "Return a dictionary describing all methods available in a class" 
136   
137      m = {} 
138      __getmethods(cls, m) 
139      return m 
140   
141 -def describe_instance(self): 
142      "Return a dictionary describing all methods available in an instance" 
143   
144      return describe_class(self.__class__) 
145   
146  # 
147  # -------------------------------------------------------------------- 
148   
149  if __name__ == "__main__": 
150   
151 -    def foo(a, b=1, *c, **d): 
152          e = a + b + c 
153          f = None 
154   
155      bar = lambda a: 0 
156   
157      # from Duncan Booth 
158 -    def baz(a, (b, c) = ('foo','bar'), (d, e, f) = (None, None, None), g = None): 
159          pass 
160   
161      print "describeParams(foo)", describeParams(foo) 
162      print "describeParams(bar)", describeParams(bar) 
163      print "describeParams(baz)", describeParams(baz) 
164   
165      print describe(foo) 
166      print describe(bar) 
167      print describe(baz) 
168