Merge pull request #1845 from fperez/magic_inspect

Fixes to inspection machinery for magics

Now that magics are generated via decorators, the inspection machinery wasn't finding data about them such as source code. Fixes that along with some refactoring, cleanup and test additions.

Closes gh-1799.

IPython/core/magics/namespace.py

@@ -79,7 +79,7 b' class NamespaceMagics(Magics):'
           In [3]: %pdef urllib.urlopen
           urllib.urlopen(url, data=None, proxies=None)
         """
-        self._inspect('pdef',parameter_s, namespaces)
+        self.shell._inspect('pdef',parameter_s, namespaces)
 
     @line_magic
     def pdoc(self, parameter_s='', namespaces=None):
@@ -87,12 +87,12 b' class NamespaceMagics(Magics):'
 
         If the given object is a class, it will print both the class and the
         constructor docstrings."""
-        self._inspect('pdoc',parameter_s, namespaces)
+        self.shell._inspect('pdoc',parameter_s, namespaces)
 
     @line_magic
     def psource(self, parameter_s='', namespaces=None):
         """Print (or run through pager) the source code for an object."""
-        self._inspect('psource',parameter_s, namespaces)
+        self.shell._inspect('psource',parameter_s, namespaces)
 
     @line_magic
     def pfile(self, parameter_s=''):
@@ -108,7 +108,7 b' class NamespaceMagics(Magics):'
         viewer."""
 
         # first interpret argument as an object name
-        out = self._inspect('pfile',parameter_s)
+        out = self.shell._inspect('pfile',parameter_s)
         # if not, try the input as a filename
         if out == 'not found':
             try:

IPython/core/oinspect.py

@@ -230,6 +230,75 b' def call_tip(oinfo, format_call=True):'
     return call_line, doc
 
 
+def find_file(obj):
+    """Find the absolute path to the file where an object was defined.
+
+    This is essentially a robust wrapper around `inspect.getabsfile`.
+
+    Returns None if no file can be found.
+
+    Parameters
+    ----------
+    obj : any Python object
+
+    Returns
+    -------
+    fname : str
+      The absolute path to the file where the object was defined.
+    """
+    # get source if obj was decorated with @decorator
+    if hasattr(obj, '__wrapped__'):
+        obj = obj.__wrapped__
+    
+    try:
+        fname = inspect.getabsfile(obj)
+    except TypeError:
+        # For an instance, the file that matters is where its class was
+        # declared.
+        if hasattr(obj, '__class__'):
+            try:
+                fname = inspect.getabsfile(obj.__class__)
+            except TypeError:
+                # Can happen for builtins
+                fname = None
+    except:
+        fname = None
+    return fname
+
+
+def find_source_lines(obj):
+    """Find the line number in a file where an object was defined.
+
+    This is essentially a robust wrapper around `inspect.getsourcelines`.
+
+    Returns None if no file can be found.
+
+    Parameters
+    ----------
+    obj : any Python object
+
+    Returns
+    -------
+    lineno : int
+      The line number where the object definition starts.
+    """
+    # get source if obj was decorated with @decorator
+    if hasattr(obj, '__wrapped__'):
+        obj = obj.__wrapped__
+    
+    try:
+        try:
+            lineno = inspect.getsourcelines(obj)[1]
+        except TypeError:
+            # For instances, try the class object like getsource() does
+            if hasattr(obj, '__class__'):
+                lineno = inspect.getsourcelines(obj.__class__)[1]
+    except:
+        return None
+
+    return lineno
+
+
 class Inspector:
     def __init__(self, color_table=InspectColors,
                  code_color_table=PyColorize.ANSICodeColors,
@@ -369,25 +438,15 b' class Inspector:'
     def pfile(self,obj,oname=''):
         """Show the whole file where an object was defined."""
 
-        try:
-            try:
-                lineno = inspect.getsourcelines(obj)[1]
-            except TypeError:
-                # For instances, try the class object like getsource() does
-                if hasattr(obj,'__class__'):
-                    lineno = inspect.getsourcelines(obj.__class__)[1]
-                    # Adjust the inspected object so getabsfile() below works
-                    obj = obj.__class__
-        except:
+        lineno = find_source_lines(obj)
+        if lineno is None:
             self.noinfo('file',oname)
             return
 
-        # We only reach this point if object was successfully queried
-
-        # run contents of file through pager starting at line
-        # where the object is defined
-        ofile = inspect.getabsfile(obj)
-
+        ofile = find_file(obj)
+        # run contents of file through pager starting at line where the object
+        # is defined, as long as the file isn't binary and is actually on the
+        # filesystem.
         if ofile.endswith(('.so', '.dll', '.pyd')):
             print 'File %r is binary, not printing.' % ofile
         elif not os.path.isfile(ofile):
@@ -570,23 +629,17 b' class Inspector:'
 
         # Filename where object was defined
         binary_file = False
-        try:
-            try:
-                fname = inspect.getabsfile(obj)
-            except TypeError:
-                # For an instance, the file that matters is where its class was
-                # declared.
-                if hasattr(obj,'__class__'):
-                    fname = inspect.getabsfile(obj.__class__)
-            if fname.endswith('<string>'):
-                fname = 'Dynamically generated function. No source code available.'
-            if fname.endswith(('.so', '.dll', '.pyd')):
-                binary_file = True
-            out['file'] = fname
-        except:
+        fname = find_file(obj)
+        if fname is None:
             # if anything goes wrong, we don't want to show source, so it's as
             # if the file was binary
             binary_file = True
+        else:
+            if fname.endswith(('.so', '.dll', '.pyd')):
+                binary_file = True
+            elif fname.endswith('<string>'):
+                fname = 'Dynamically generated function. No source code available.'
+            out['file'] = fname
 
         # reconstruct the function definition and print it:
         defln = self._getdef(obj, oname)

IPython/core/tests/test_oinspect.py

@@ -14,6 +14,7 b''
 from __future__ import print_function
 
 # Stdlib imports
+import os
 
 # Third-party imports
 import nose.tools as nt
@@ -24,8 +25,10 b' from IPython.core.magic import (Magics, magics_class, line_magic,'
                                 cell_magic, line_cell_magic,
                                 register_line_magic, register_cell_magic,
                                 register_line_cell_magic)
+from IPython.external.decorator import decorator
 from IPython.utils import py3compat
 
+
 #-----------------------------------------------------------------------------
 # Globals and constants
 #-----------------------------------------------------------------------------
@@ -37,6 +40,58 b' ip = get_ipython()'
 # Local utilities
 #-----------------------------------------------------------------------------
 
+# WARNING: since this test checks the line number where a function is
+# defined, if any code is inserted above, the following line will need to be
+# updated.  Do NOT insert any whitespace between the next line and the function
+# definition below.
+THIS_LINE_NUMBER = 47  # Put here the actual number of this line
+def test_find_source_lines():
+    nt.assert_equal(oinspect.find_source_lines(test_find_source_lines), 
+                    THIS_LINE_NUMBER+1)
+
+
+def test_find_file():
+    nt.assert_equal(oinspect.find_file(test_find_file),
+                    os.path.abspath(__file__))
+
+
+def test_find_file_decorated1():
+
+    @decorator
+    def noop1(f):
+        def wrapper():
+            return f(*a, **kw)
+        return wrapper
+
+    @noop1
+    def f(x):
+        "My docstring"
+    
+    nt.assert_equal(oinspect.find_file(f),
+                    os.path.abspath(__file__))
+    nt.assert_equal(f.__doc__, "My docstring")
+
+
+def test_find_file_decorated2():
+
+    @decorator
+    def noop2(f, *a, **kw):
+        return f(*a, **kw)
+
+    @noop2
+    def f(x):
+        "My docstring 2"
+    
+    nt.assert_equal(oinspect.find_file(f),
+                    os.path.abspath(__file__))
+    nt.assert_equal(f.__doc__, "My docstring 2")
+    
+
+def test_find_file_magic():
+    run = ip.find_line_magic('run')
+    nt.assert_not_equal(oinspect.find_file(run), None)
+
+
 # A few generic objects we can then inspect in the tests below
 
 class Call(object):