Minor changes to Python binding generator for cleanliness.

This hides all of our internal functions and moves the imports to
the top level to stop linter complaints in downstream packages.

src/cpptypes/create_py_bindings.py

@@ -103,8 +103,13 @@ def create_py_bindings(all_functions: dict, output_path: str, dll_prefix: str):
 
 import os
 import ctypes as ct
+""")
+        if with_numpy:
+            handle.write("""import numpy as np
+""")
 
-def catch_errors(f):
+        handle.write("""
+def _catch_errors(f):
     def wrapper(*args):
         errcode = ct.c_int32(0)
         errmsg = ct.c_char_p(0)
@@ -133,8 +138,7 @@ def wrapper(*args):
         if with_numpy:
             handle.write("""
 
-import numpy as np
-def np2ct(x, expected, contiguous=True):
+def _np2ct(x, expected, contiguous=True):
     if not isinstance(x, np.ndarray):
         raise ValueError('expected a NumPy array')
     if x.dtype != expected:
@@ -185,13 +189,13 @@ def np2ct(x, expected, contiguous=True):
                             args += x.type.base_type
                         if "non_contig" in x.type.tags:
                             args += ", contiguous=False"
-                        argnames2.append("np2ct(" + x.name + args + ")")
+                        argnames2.append("_np2ct(" + x.name + args + ")")
                     else:
                         argnames2.append(x.name)
             else:
                 argnames2 = argnames
 
             handle.write("\n\ndef " + k + "(" + ", ".join(argnames) + """):
-    return catch_errors(lib.py_""" + k + ")(" + ", ".join(argnames2) + """)""")
+    return _catch_errors(lib.py_""" + k + ")(" + ", ".join(argnames2) + """)""")
 
     return

tests/test_create_py_bindings.py

@@ -99,11 +99,11 @@ def test_create_py_bindings():
 
             elif line == "def cocoa_best_function(chino, rize, midori):":
                 found_cocoa_def = True
-                assert handle.readline().strip() == "return catch_errors(lib.py_cocoa_best_function)(np2ct(chino, np.float64), rize, midori)"
+                assert handle.readline().strip() == "return _catch_errors(lib.py_cocoa_best_function)(_np2ct(chino, np.float64), rize, midori)"
 
             elif line == "def syaro_second_function(chiya, moka, maya, megu):":
                 found_syaro_def = True
-                assert handle.readline().strip() == "return catch_errors(lib.py_syaro_second_function)(chiya, moka, np2ct(maya, np.int32, contiguous=False), np2ct(megu, np.float32))"
+                assert handle.readline().strip() == "return _catch_errors(lib.py_syaro_second_function)(chiya, moka, _np2ct(maya, np.int32, contiguous=False), _np2ct(megu, np.float32))"
 
     assert found_cocoa_types
     assert found_syaro_types
@@ -153,11 +153,11 @@ def test_create_py_bindings():
 
             elif line == "def cocoa_best_function(chino, rize, midori):":
                 found_cocoa_def = True
-                assert handle.readline().strip() == "return catch_errors(lib.py_cocoa_best_function)(chino, rize, midori)"
+                assert handle.readline().strip() == "return _catch_errors(lib.py_cocoa_best_function)(chino, rize, midori)"
 
             elif line == "def syaro_second_function(chiya, moka, maya, megu):":
                 found_syaro_def = True
-                assert handle.readline().strip() == "return catch_errors(lib.py_syaro_second_function)(chiya, moka, maya, megu)"
+                assert handle.readline().strip() == "return _catch_errors(lib.py_syaro_second_function)(chiya, moka, maya, megu)"
 
     assert found_cocoa_types
     assert found_syaro_types