ENH: f2py: add --f2cmap option for specifying the name of .f2py_f2cmap

Previously, f2py loaded the type mappings from a file ``.f2py_f2cmap``
in current directory, at import time.

Make the file name customizable by adding a ``--f2cmap`` command line
option, and postpone loading the file to f2py.run_main().

Moreover, restore the default type mapping in f2py.run_main() before
loading the customizations, so that multiple calls to f2py.run_main() do
not interfere with each other. (For example, numpy.distutils calls f2py
multiple times in the same process.)

1 files changed, 20 insertions, 8 deletions

diff --git a/numpy/f2py/capi_maps.py b/numpy/f2py/capi_maps.py
index c41dd77c6..ce79f680f 100644
--- a/numpy/f2py/capi_maps.py
+++ b/numpy/f2py/capi_maps.py
@@ -179,17 +179,29 @@ f2cmap_all = {'real': {'': 'float', '4': 'float', '8': 'double',
               'character': {'': 'string'}
               }
 
-if os.path.isfile('.f2py_f2cmap'):
+f2cmap_default = copy.deepcopy(f2cmap_all)
+
+
+def load_f2cmap_file(f2cmap_file):
+    global f2cmap_all
+
+    f2cmap_all = copy.deepcopy(f2cmap_default)
+
+    if f2cmap_file is None:
+        # Default value
+        f2cmap_file = '.f2py_f2cmap'
+        if not os.path.isfile(f2cmap_file):
+            return
+
     # User defined additions to f2cmap_all.
-    # .f2py_f2cmap must contain a dictionary of dictionaries, only.  For
+    # f2cmap_file must contain a dictionary of dictionaries, only.  For
     # example, {'real':{'low':'float'}} means that Fortran 'real(low)' is
     # interpreted as C 'float'.  This feature is useful for F90/95 users if
     # they use PARAMETERSs in type specifications.
     try:
-        outmess('Reading .f2py_f2cmap ...\n')
-        f = open('.f2py_f2cmap', 'r')
-        d = eval(f.read(), {}, {})
-        f.close()
+        outmess('Reading f2cmap from {!r} ...\n'.format(f2cmap_file))
+        with open(f2cmap_file, 'r') as f:
+            d = eval(f.read(), {}, {})
         for k, d1 in list(d.items()):
             for k1 in list(d1.keys()):
                 d1[k1.lower()] = d1[k1]
@@ -208,10 +220,10 @@ if os.path.isfile('.f2py_f2cmap'):
                 else:
                     errmess("\tIgnoring map {'%s':{'%s':'%s'}}: '%s' must be in %s\n" % (
                         k, k1, d[k][k1], d[k][k1], list(c2py_map.keys())))
-        outmess('Successfully applied user defined changes from .f2py_f2cmap\n')
+        outmess('Successfully applied user defined f2cmap changes\n')
     except Exception as msg:
         errmess(
-            'Failed to apply user defined changes from .f2py_f2cmap: %s. Skipping.\n' % (msg))
+            'Failed to apply user defined f2cmap changes: %s. Skipping.\n' % (msg))
 
 cformat_map = {'double': '%g',
                'float': '%g',