Allow running generate_code.py from anywhere

Previously you had to run it from inside the same directory, but
it's less likely to mess up newbs if you can run it from anywhere.

Author: Garrett-R

pandas/src/generate_code.py

@@ -6,6 +6,7 @@
 """
 
 from __future__ import print_function
+import os
 from pandas.compat import StringIO
 import numpy as np
 
@@ -2536,7 +2537,12 @@ def generate_from_template(template, exclude=None):
                   take_2d_multi_template]
 
 
-def generate_take_cython_file(path='generated.pyx'):
+def generate_take_cython_file():
+    # Put `generated.pyx` in the same directory as this file
+    directory = os.path.dirname(os.path.realpath(__file__))
+    filename = 'generated.pyx'
+    path = os.path.join(directory, filename)
+
     with open(path, 'w') as f:
         print(warning_to_new_contributors, file=f)
         print(header, file=f)