split files models.py and test.py

In order ease development for all developers and management of the library
split each class into its dedicated file.

split the file `test.py` to simplify management of tests.
One file per class being tested.

! This is a breaking change ! user will be required to update their code
in order to match library new layout.

gspread/__init__.py

@@ -15,7 +15,9 @@
 
 from .auth import oauth, service_account, service_account_from_dict
 from .client import Client
-from .models import Spreadsheet, Worksheet, Cell
+from .spreadsheet import Spreadsheet
+from .worksheet import Worksheet
+from .cell import Cell
 
 from .exceptions import (
     GSpreadException,

gspread/cell.py

@@ -0,0 +1,82 @@
+# -*- coding: utf-8 -*-
+
+"""
+gspread.models
+~~~~~~~~~~~~~~
+
+This module contains common cells' models.
+
+"""
+
+from .utils import (
+    a1_to_rowcol,
+    numericise,
+    rowcol_to_a1,
+)
+
+
+class Cell(object):
+    """An instance of this class represents a single cell
+    in a :class:`worksheet <gspread.models.Worksheet>`.
+    """
+
+    def __init__(self, row, col, value=""):
+        self._row = row
+        self._col = col
+
+        #: Value of the cell.
+        self.value = value
+
+    @classmethod
+    def from_address(cls, label, value=""):
+        return cls(*a1_to_rowcol(label), value=value)
+
+    def __repr__(self):
+        return "<%s R%sC%s %s>" % (
+            self.__class__.__name__,
+            self.row,
+            self.col,
+            repr(self.value),
+        )
+
+    @property
+    def row(self):
+        """Row number of the cell."""
+        return self._row
+
+    @property
+    def col(self):
+        """Column number of the cell."""
+        return self._col
+
+    @property
+    def numeric_value(self):
+        numeric_value = numericise(self.value, default_blank=None)
+
+        # if could not convert, return None
+        if type(numeric_value) == int or type(numeric_value) == float:
+            return numeric_value
+        else:
+            return None
+
+    @property
+    def address(self):
+        """Cell address in A1 notation."""
+        return rowcol_to_a1(self.row, self.col)
+
+    @property
+    def input_value(self):
+        """.. deprecated:: 2.0
+
+        This feature is not supported in Sheets API v4.
+        """
+        import warnings
+
+        warnings.warn(
+            "Cell.input_value is deprecated, "
+            "this feature is not supported in Sheets API v4. "
+            "Please use `value_render_option` when you "
+            "Retrieve `Cell` objects (e.g. in `Worksheet.range()` method).",
+            DeprecationWarning,
+            stacklevel=2,
+        )

gspread/client.py

@@ -12,7 +12,7 @@
 from google.auth.transport.requests import AuthorizedSession
 
 from .exceptions import APIError, SpreadsheetNotFound
-from .models import Spreadsheet
+from .spreadsheet import Spreadsheet
 from .utils import convert_credentials, extract_id_from_url, finditem
 
 from .urls import (