Things to use in Python 3(datawhatnow.com)

  >>> x = 1
  >>> f"{x}"
  '1'

  >>> "{x}".format(x=x)
  '1'

  >>> "{}".format(x)
  '1'

  F"My string with {interpolated_value}"
  f'My string with {interpolated_value}'

  "This is my ${interpolated_value} string"
  'This is my plain old string'

   print('foo=',foo)

   print('f{foo=}')

    Python 2.7.15 (default, Jun 27 2018, 13:05:28) 
    [GCC 8.1.1 20180531] on linux2
    Type "help", "copyright", "credits" or "license" for more information.
    >>> class Foo:
    ...   pass
    ... 
    >>> Foo
    <class __main__.Foo at 0x6218e384ee88>
    >>> class Bar(object):
    ...   pass
    ... 
    >>> Bar
    <class '__main__.Bar'>
    >>> isinstance(Bar, type)
    True
    >>> isinstance(Foo, type)
    False

    In [21]: @enum.unique 
        ...: class Animal(enum.Enum): 
        ...:     DOG = 1 
        ...:     CAT = 2 
        ...:     PIG = 2 
        ...:                                                                                                                                                              
    ---------------------------------------------------------------------------
    ValueError                                Traceback (most recent call last)
    <ipython-input-21-cbc1625bb41c> in <module>
        1 @enum.unique
    ----> 2 class Animal(enum.Enum):
        3     DOG = 1
        4     CAT = 2
        5     PIG = 2

    ~/.virtualenvs/py3/lib/python3.6/enum.py in unique(enumeration)
        834                 ["%s -> %s" % (alias, name) for (alias, name) in duplicates])
        835         raise ValueError('duplicate values found in %r: %s' %
    --> 836                 (enumeration, alias_details))
        837     return enumeration
        838 

    ValueError: duplicate values found in <enum 'Animal'>: PIG -> CAT