8. Data Types

The modules described in this chapter provide a variety of specialized data types such as dates and times, fixed-type arrays, heap queues, synchronized queues, and sets.

Python also provides some built-in data types, in particular, dict, list, set and frozenset, and tuple. The str class is used to hold Unicode strings, and the bytes class is used to hold binary data.

The following modules are documented in this chapter:

• 8.1. datetime — Basic date and time types
  • MINYEAR
  • MAXYEAR
  • 8.1.1. Available Types
  • 8.1.2. timedelta Objects
    • timedelta
      • timedelta.min
      • timedelta.max
      • timedelta.resolution
      • timedelta.total_seconds()
  • 8.1.3. date Objects
    • date
      • date.today()
      • date.fromtimestamp()
      • date.fromordinal()
      • date.min
      • date.max
      • date.resolution
      • date.year
      • date.month
      • date.day
      • date.replace()
      • date.timetuple()
      • date.toordinal()
      • date.weekday()
      • date.isoweekday()
      • date.isocalendar()
      • date.isoformat()
      • date.__str__()
      • date.ctime()
      • date.strftime()
      • date.__format__()
  • 8.1.4. datetime Objects
    • datetime
      • datetime.today()
      • datetime.now()
      • datetime.utcnow()
      • datetime.fromtimestamp()
      • datetime.utcfromtimestamp()
      • datetime.fromordinal()
      • datetime.combine()
      • datetime.strptime()
      • datetime.min
      • datetime.max
      • datetime.resolution
      • datetime.year
      • datetime.month
      • datetime.day
      • datetime.hour
      • datetime.minute
      • datetime.second
      • datetime.microsecond
      • datetime.tzinfo
      • datetime.fold
      • datetime.date()
      • datetime.time()
      • datetime.timetz()
      • datetime.replace()
      • datetime.astimezone()
      • datetime.utcoffset()
      • datetime.dst()
      • datetime.tzname()
      • datetime.timetuple()
      • datetime.utctimetuple()
      • datetime.toordinal()
      • datetime.timestamp()
      • datetime.weekday()
      • datetime.isoweekday()
      • datetime.isocalendar()
      • datetime.isoformat()
      • datetime.__str__()
      • datetime.ctime()
      • datetime.strftime()
      • datetime.__format__()
  • 8.1.5. time Objects
    • time
      • time.min
      • time.max
      • time.resolution
      • time.hour
      • time.minute
      • time.second
      • time.microsecond
      • time.tzinfo
      • time.fold
      • time.replace()
      • time.isoformat()
      • time.__str__()
      • time.strftime()
      • time.__format__()
      • time.utcoffset()
      • time.dst()
      • time.tzname()
  • 8.1.6. tzinfo Objects
    • tzinfo
      • tzinfo.utcoffset()
      • tzinfo.dst()
      • tzinfo.tzname()
      • tzinfo.fromutc()
  • 8.1.7. timezone Objects
    • timezone
      • timezone.utcoffset()
      • timezone.tzname()
      • timezone.dst()
      • timezone.fromutc()
      • timezone.utc
  • 8.1.8. strftime() and strptime() Behavior
• 8.2. calendar — General calendar-related functions
  • Calendar
    • Calendar.iterweekdays()
    • Calendar.itermonthdates()
    • Calendar.itermonthdays2()
    • Calendar.itermonthdays()
    • Calendar.monthdatescalendar()
    • Calendar.monthdays2calendar()
    • Calendar.monthdayscalendar()
    • Calendar.yeardatescalendar()
    • Calendar.yeardays2calendar()
    • Calendar.yeardayscalendar()
  • TextCalendar
    • TextCalendar.formatmonth()
    • TextCalendar.prmonth()
    • TextCalendar.formatyear()
    • TextCalendar.pryear()
  • HTMLCalendar
    • HTMLCalendar.formatmonth()
    • HTMLCalendar.formatyear()
    • HTMLCalendar.formatyearpage()
  • LocaleTextCalendar
  • LocaleHTMLCalendar
  • setfirstweekday()
  • firstweekday()
  • isleap()
  • leapdays()
  • weekday()
  • weekheader()
  • monthrange()
  • monthcalendar()
  • prmonth()
  • month()
  • prcal()
  • calendar()
  • timegm()
  • day_name
  • day_abbr
  • month_name
  • month_abbr
• 8.3. collections — Container datatypes
  • 8.3.1. ChainMap objects
    • ChainMap
      • ChainMap.maps
      • ChainMap.new_child()
      • ChainMap.parents
    • 8.3.1.1. ChainMap Examples and Recipes
  • 8.3.2. Counter objects
    • Counter
      • Counter.elements()
      • Counter.most_common()
      • Counter.subtract()
      • Counter.fromkeys()
      • Counter.update()
  • 8.3.3. deque objects
    • deque
      • deque.append()
      • deque.appendleft()
      • deque.clear()
      • deque.copy()
      • deque.count()
      • deque.extend()
      • deque.extendleft()
      • deque.index()
      • deque.insert()
      • deque.pop()
      • deque.popleft()
      • deque.remove()
      • deque.reverse()
      • deque.rotate()
      • deque.maxlen
    • 8.3.3.1. deque Recipes
  • 8.3.4. defaultdict objects
    • defaultdict
      • defaultdict.__missing__()
      • defaultdict.default_factory
    • 8.3.4.1. defaultdict Examples
  • 8.3.5. namedtuple() Factory Function for Tuples with Named Fields
    • namedtuple()
    • somenamedtuple._make()
    • somenamedtuple._asdict()
    • somenamedtuple._replace()
    • somenamedtuple._source
    • somenamedtuple._fields
  • 8.3.6. OrderedDict objects
    • OrderedDict
      • OrderedDict.popitem()
      • OrderedDict.move_to_end()
    • 8.3.6.1. OrderedDict Examples and Recipes
  • 8.3.7. UserDict objects
    • UserDict
      • UserDict.data
  • 8.3.8. UserList objects
    • UserList
      • UserList.data
  • 8.3.9. UserString objects
    • UserString
• 8.4. collections.abc — Abstract Base Classes for Containers
  • 8.4.1. Collections Abstract Base Classes
    • Container
    • Hashable
    • Sized
    • Callable
    • Iterable
    • Collection
    • Iterator
    • Reversible
    • Generator
    • Sequence
    • MutableSequence
    • ByteString
    • Set
    • MutableSet
    • Mapping
    • MutableMapping
    • MappingView
    • ItemsView
    • KeysView
    • ValuesView
    • Awaitable
    • Coroutine
    • AsyncIterable
    • AsyncIterator
    • AsyncGenerator
• 8.5. heapq — Heap queue algorithm
  • heappush()
  • heappop()
  • heappushpop()
  • heapify()
  • heapreplace()
  • merge()
  • nlargest()
  • nsmallest()
  • 8.5.1. Basic Examples
  • 8.5.2. Priority Queue Implementation Notes
  • 8.5.3. Theory
• 8.6. bisect — Array bisection algorithm
  • bisect_left()
  • bisect_right()
  • bisect()
  • insort_left()
  • insort_right()
  • insort()
  • 8.6.1. Searching Sorted Lists
  • 8.6.2. Other Examples
• 8.7. array — Efficient arrays of numeric values
  • array
    • array.typecode
    • array.itemsize
    • array.append()
    • array.buffer_info()
    • array.byteswap()
    • array.count()
    • array.extend()
    • array.frombytes()
    • array.fromfile()
    • array.fromlist()
    • array.fromstring()
    • array.fromunicode()
    • array.index()
    • array.insert()
    • array.pop()
    • array.remove()
    • array.reverse()
    • array.tobytes()
    • array.tofile()
    • array.tolist()
    • array.tostring()
    • array.tounicode()
  • typecodes
• 8.8. weakref — Weak references
  • ref
    • ref.__callback__
  • proxy()
  • getweakrefcount()
  • getweakrefs()
  • WeakKeyDictionary
    • WeakKeyDictionary.keyrefs()
  • WeakValueDictionary
    • WeakValueDictionary.valuerefs()
  • WeakSet
  • WeakMethod
  • finalize
    • finalize.__call__()
    • finalize.detach()
    • finalize.peek()
    • finalize.alive
    • finalize.atexit
  • ReferenceType
  • ProxyType
  • CallableProxyType
  • ProxyTypes
  • ReferenceError
  • 8.8.1. Weak Reference Objects
  • 8.8.2. Example
  • 8.8.3. Finalizer Objects
  • 8.8.4. Comparing finalizers with __del__() methods
• 8.9. types — Dynamic type creation and names for built-in types
  • 8.9.1. Dynamic Type Creation
    • new_class()
    • prepare_class()
  • 8.9.2. Standard Interpreter Types
    • FunctionType
    • LambdaType
    • GeneratorType
    • CoroutineType
    • AsyncGeneratorType
    • CodeType
    • MethodType
    • BuiltinFunctionType
    • BuiltinMethodType
    • ModuleType
      • ModuleType.__doc__
      • ModuleType.__loader__
      • ModuleType.__name__
      • ModuleType.__package__
    • TracebackType
    • FrameType
    • GetSetDescriptorType
    • MemberDescriptorType
    • MappingProxyType
      • MappingProxyType.copy()
      • MappingProxyType.get()
      • MappingProxyType.items()
      • MappingProxyType.keys()
      • MappingProxyType.values()
  • 8.9.3. Additional Utility Classes and Functions
    • SimpleNamespace
    • DynamicClassAttribute()
  • 8.9.4. Coroutine Utility Functions
    • coroutine()
• 8.10. copy — Shallow and deep copy operations
  • copy()
  • deepcopy()
  • error
• 8.11. pprint — Data pretty printer
  • PrettyPrinter
  • pformat()
  • pprint()
  • isreadable()
  • isrecursive()
  • saferepr()
  • 8.11.1. PrettyPrinter Objects
    • PrettyPrinter.pformat()
    • PrettyPrinter.pprint()
    • PrettyPrinter.isreadable()
    • PrettyPrinter.isrecursive()
    • PrettyPrinter.format()
  • 8.11.2. Example
• 8.12. reprlib — Alternate repr() implementation
  • Repr
  • aRepr
  • repr()
  • recursive_repr()
  • 8.12.1. Repr Objects
    • Repr.maxlevel
    • Repr.maxdict
    • Repr.maxlist
    • Repr.maxtuple
    • Repr.maxset
    • Repr.maxfrozenset
    • Repr.maxdeque
    • Repr.maxarray
    • Repr.maxlong
    • Repr.maxstring
    • Repr.maxother
    • Repr.repr()
    • Repr.repr1()
  • 8.12.2. Subclassing Repr Objects
• 8.13. enum — Support for enumerations
  • 8.13.1. Module Contents
    • Enum
    • IntEnum
    • IntFlag
    • Flag
    • unique()
    • auto
  • 8.13.2. Creating an Enum
  • 8.13.3. Programmatic access to enumeration members and their attributes
  • 8.13.4. Duplicating enum members and values
  • 8.13.5. Ensuring unique enumeration values
    • unique()
  • 8.13.6. Using automatic values
  • 8.13.7. Iteration
  • 8.13.8. Comparisons
  • 8.13.9. Allowed members and attributes of enumerations
  • 8.13.10. Restricted subclassing of enumerations
  • 8.13.11. Pickling
  • 8.13.12. Functional API
  • 8.13.13. Derived Enumerations
    • 8.13.13.1. IntEnum
    • 8.13.13.2. IntFlag
    • 8.13.13.3. Flag
    • 8.13.13.4. Others
  • 8.13.14. Interesting examples
    • 8.13.14.1. Omitting values
      • 8.13.14.1.1. Using auto
      • 8.13.14.1.2. Using object
      • 8.13.14.1.3. Using a descriptive string
      • 8.13.14.1.4. Using a custom __new__()
    • 8.13.14.2. OrderedEnum
    • 8.13.14.3. DuplicateFreeEnum
    • 8.13.14.4. Planet
  • 8.13.15. How are Enums different?
    • 8.13.15.1. Enum Classes
    • 8.13.15.2. Enum Members (aka instances)
    • 8.13.15.3. Finer Points
      • 8.13.15.3.1. Supported __dunder__ names
      • 8.13.15.3.2. Supported _sunder_ names
      • 8.13.15.3.3. Enum member type
      • 8.13.15.3.4. Boolean value of Enum classes and members
      • 8.13.15.3.5. Enum classes with methods
      • 8.13.15.3.6. Combining members of Flag