fix backward `f, nb` args for nbformat.write

IPython/core/magics/basic.py

@@ -608,4 +608,4 b' Defaulting color scheme to \'NoColor\'"""'
                 ))
             nb = v4.new_notebook(cells=cells)
             with io.open(args.filename, 'w', encoding='utf-8') as f:
-                write(f, nb, version=4)
+                write(nb, f, version=4)

IPython/html/nbconvert/tests/test_nbconvert_handlers.py

@@ -67,7 +67,7 b' class APITest(NotebookTestBase):'
         
         with io.open(pjoin(nbdir, 'foo', 'testnb.ipynb'), 'w',
                      encoding='utf-8') as f:
-            write(f, nb, version=4)
+            write(nb, f, version=4)
 
         self.nbconvert_api = NbconvertAPI(self.base_url())
 

IPython/html/services/contents/filemanager.py

@@ -303,7 +303,7 b' class FileContentsManager(ContentsManager):'
             nb['metadata']['name'] = u''
 
         with atomic_writing(os_path, encoding='utf-8') as f:
-            nbformat.write(f, nb, version=nbformat.NO_CONVERT)
+            nbformat.write(nb, f, version=nbformat.NO_CONVERT)
 
     def _save_file(self, os_path, model, name='', path=''):
         """save a non-notebook file"""

IPython/html/services/contents/tests/test_contents_api.py

@@ -144,7 +144,7 b' class APITest(NotebookTestBase):'
             with io.open(pjoin(nbdir, d, '%s.ipynb' % name), 'w',
                          encoding='utf-8') as f:
                 nb = new_notebook()
-                write(f, nb, version=4)
+                write(nb, f, version=4)
 
             # create a text file
             with io.open(pjoin(nbdir, d, '%s.txt' % name), 'w',

IPython/html/services/sessions/tests/test_sessions_api.py

@@ -64,7 +64,7 b' class SessionAPITest(NotebookTestBase):'
         with io.open(pjoin(nbdir, 'foo', 'nb1.ipynb'), 'w',
                      encoding='utf-8') as f:
             nb = new_notebook()
-            write(f, nb, version=4)
+            write(nb, f, version=4)
 
         self.sess_api = SessionAPI(self.base_url())
 

IPython/html/tests/test_files.py

@@ -74,7 +74,7 b' class FilesTest(NotebookTestBase):'
 
         with io.open(pjoin(nbdir, 'testnb.ipynb'), 'w', 
             encoding='utf-8') as f:
-            write(f, nb, version=4)
+            write(nb, f, version=4)
 
         with io.open(pjoin(nbdir, 'test.bin'), 'wb') as f:
             f.write(b'\xff' + os.urandom(5))

IPython/nbconvert/exporters/tests/test_latex.py

@@ -95,7 +95,7 b' class TestLatexExporter(ExportersTestsBase):'
         with TemporaryDirectory() as td:
             nbfile = os.path.join(td, notebook_name)
             with open(nbfile, 'w') as f:
-                write(f, nb, 4)
+                write(nb, f, 4)
 
             (output, resources) = LatexExporter(template_file='article').from_filename(nbfile)
             assert len(output) > 0

IPython/nbconvert/tests/base.py

@@ -103,7 +103,7 b' class TestsBase(unittest.TestCase):'
     def create_empty_notebook(self, path):
         nb = v4.new_notebook()
         with io.open(path, 'w', encoding='utf-8') as f:
-            write(f, nb, 4)
+            write(nb, f, 4)
 
     def copy_files_to(self, copy_filenames, dest='.'):
         "Copy test files into the destination directory"

IPython/nbformat/__init__.py

@@ -123,17 +123,17 b' def read(fp, as_version, **kwargs):'
     return reads(fp.read(), as_version, **kwargs)
 
 
-def write(fp, nb, version=NO_CONVERT, **kwargs):
+def write(nb, fp, version=NO_CONVERT, **kwargs):
     """Write a notebook to a file in a given nbformat version.
     
     The file-like object must accept unicode input.
     
     Parameters
     ----------
-    fp : file
-        Any file-like object with a write method that accepts unicode.
     nb : NotebookNode
         The notebook to write.
+    fp : file
+        Any file-like object with a write method that accepts unicode.
     version : int, optional
         The nbformat version to write.
         If nb is not this version, it will be converted.

IPython/nbformat/sign.py

@@ -311,7 +311,7 b' class TrustNotebookApp(BaseIPythonApplication):'
             print("Signing notebook: %s" % notebook_path)
             self.notary.sign(nb)
             with atomic_writing(notebook_path) as f:
-                write(f, nb, NO_CONVERT)
+                write(nb, f, NO_CONVERT)
     
     def generate_new_key(self):
         """Generate a new notebook signature key"""