Python data type (4) dictionary: dict

The knowledge shared in this article is the basic concept, common operations, and examples of the Dictionary (dict) in Python data types. It is very useful for you to understand the dictionary dict, I hope you will like it. I. Basic Data Types

Integer: int
String: str (Note: \ t is equal to a tab key)
Boolean value: bool
List: list
List []
Ancestor: tuple
Ancestor use ()
Dictionary: dict

Note: All data types exist in the desired class columns. The list can be modified and the ancestor cannot be modified in the same way as the list function.

Ii. All data types in the dictionary:

Common Operations:

Index, add, delete, key, value, key-value pair, cycle, Length

class dict(object):  """  dict() -> new empty dictionary  dict(mapping) -> new dictionary initialized from a mapping object's    (key, value) pairs  dict(iterable) -> new dictionary initialized as if via:    d = {}    for k, v in iterable:      d[k] = v  dict(**kwargs) -> new dictionary initialized with the name=value pairs    in the keyword argument list. For example: dict(one=1, two=2)  """  def clear(self): # real signature unknown; restored from __doc__    """ D.clear() -> None. Remove all items from D. """    pass  def copy(self): # real signature unknown; restored from __doc__    """ D.copy() -> a shallow copy of D """    pass  @staticmethod # known case  def fromkeys(*args, **kwargs): # real signature unknown    """ Returns a new dict with keys from iterable and values equal to value. """    pass  def get(self, k, d=None): # real signature unknown; restored from __doc__    """ D.get(k[,d]) -> D[k] if k in D, else d. d defaults to None. """    pass  def items(self): # real signature unknown; restored from __doc__    """ D.items() -> a set-like object providing a view on D's items """    pass  def keys(self): # real signature unknown; restored from __doc__    """ D.keys() -> a set-like object providing a view on D's keys """    pass  def pop(self, k, d=None): # real signature unknown; restored from __doc__    """    D.pop(k[,d]) -> v, remove specified key and return the corresponding value.    If key is not found, d is returned if given, otherwise KeyError is raised    """    pass  def popitem(self): # real signature unknown; restored from __doc__    """    D.popitem() -> (k, v), remove and return some (key, value) pair as a    2-tuple; but raise KeyError if D is empty.    """    pass  def setdefault(self, k, d=None): # real signature unknown; restored from __doc__    """ D.setdefault(k[,d]) -> D.get(k,d), also set D[k]=d if k not in D """    pass  def update(self, E=None, **F): # known special case of dict.update    """    D.update([E, ]**F) -> None. Update D from dict/iterable E and F.    If E is present and has a .keys() method, then does: for k in E: D[k] = E[k]    If E is present and lacks a .keys() method, then does: for k, v in E: D[k] = v    In either case, this is followed by: for k in F: D[k] = F[k]    """    pass  def values(self): # real signature unknown; restored from __doc__    """ D.values() -> an object providing a view on D's values """    pass  def __contains__(self, *args, **kwargs): # real signature unknown    """ True if D has a key k, else False. """    pass  def __delitem__(self, *args, **kwargs): # real signature unknown    """ Delete self[key]. """    pass  def __eq__(self, *args, **kwargs): # real signature unknown    """ Return self==value. """    pass  def __getattribute__(self, *args, **kwargs): # real signature unknown    """ Return getattr(self, name). """    pass  def __getitem__(self, y): # real signature unknown; restored from __doc__    """ x.__getitem__(y) <==> x[y] """    pass  def __ge__(self, *args, **kwargs): # real signature unknown    """ Return self>=value. """    pass  def __gt__(self, *args, **kwargs): # real signature unknown    """ Return self>value. """    pass  def __init__(self, seq=None, **kwargs): # known special case of dict.__init__    """    dict() -> new empty dictionary    dict(mapping) -> new dictionary initialized from a mapping object's      (key, value) pairs    dict(iterable) -> new dictionary initialized as if via:      d = {}      for k, v in iterable:        d[k] = v    dict(**kwargs) -> new dictionary initialized with the name=value pairs      in the keyword argument list. For example: dict(one=1, two=2)    # (copied from class doc)    """    pass  def __iter__(self, *args, **kwargs): # real signature unknown    """ Implement iter(self). """    pass  def __len__(self, *args, **kwargs): # real signature unknown    """ Return len(self). """    pass  def __le__(self, *args, **kwargs): # real signature unknown    """ Return self<=value. """    pass  def __lt__(self, *args, **kwargs): # real signature unknown    """ Return self
 
   size of D in memory, in bytes """    pass  __hash__ = None
 

Iii. Examples of all dictionary data types

User_info = {0: "zhangyanlin", "age": "18", 2: "pythoner"} # Get all keyprint (user_info.keys ()) # Getting all valuesprint (user_info.values () # getting all keys and valuesprint (user_info.items () clear all content user_info.clear () print (user_info) # get gets a value based on the key. If the key does not exist, you can specify a default value val = user_info.get ('age') print (val) # update the batch update test = {'A': 111, 'B': 222} user_info.update (test) print (user_info)

Iv. Index

# If no key exists, the error user_info = {"name": 'hangyanlin', "age": 18, "job ": 'pythoner'} print (user_info ['name'])

V. for Loop

# Loop user_info = {0: "zhangyanlin", "age": "18", 2: "pythoner"} for I in user_info: print (I) # loop output all input values for k, v in user_info.items (): print (k) print (v)

The above is all the content of this article. I hope it will be helpful for you to master the Python data structure.