doc: fix typos in the USAGE section and docstrings

Adapted commit of FedorSelitsky <[email protected]>
from PR #14

Signed-off-by: Jakub Filak <[email protected]>

Author: fedarsialitski

USAGE.md

@@ -17,7 +17,7 @@ client = pyodata.Client(SERVICE_URL, requests.Session())
 ```python
 # Get employee identified by 1 and print employee first name
 employee1 = client.entity_sets.Employees.get_entity(1).execute()
-print employee1.FirstName
+print(employee1.FirstName)
 ```
 
 ### Get one entity identified by its key value which is not scalar
@@ -33,7 +33,7 @@ print(order.Quantity)
 ```python
 
 # Print unique identification (Id) and last name of all cemployees
-employees = client.entity_sets.Employees.get_entities().select('EmployeeID,LasttName').execute()
+employees = client.entity_sets.Employees.get_entities().select('EmployeeID,LastName').execute()
 for employee in employees:
     print(employee.EmployeeID, employee.LastName)
 ```

pyodata/v2/service.py

@@ -321,7 +321,7 @@ def __init__(self, handler, entity_key, entity_set_proxy):
         self._logger.debug('New instance of EntityGetRequest for last segment: %s', self._entity_set_proxy.last_segment)
 
     def nav(self, nav_property):
-        """Navigates to given navigation property and returns the EntritySetProxy"""
+        """Navigates to given navigation property and returns the EntitySetProxy"""
         return self._entity_set_proxy.nav(nav_property, self._entity_key)
 
     def select(self, select):
@@ -761,7 +761,7 @@ def __getattr__(self, attr):
                                      .format(self._entity_type.name, attr, str(ex)))
 
     def nav(self, nav_property):
-        """Navigates to given navigation property and returns the EntritySetProxy"""
+        """Navigates to given navigation property and returns the EntitySetProxy"""
 
         # for now duplicated with simillar method in entity set proxy class
         try:
@@ -971,7 +971,7 @@ def last_segment(self):
         return self._parent_last_segment + entity_set_name
 
     def nav(self, nav_property, key):
-        """Navigates to given navigation property and returns the EntritySetProxy"""
+        """Navigates to given navigation property and returns the EntitySetProxy"""
 
         try:
             navigation_property = self._entity_set.entity_type.nav_proprty(nav_property)