This case is to create a deck of 52 playing cards by Python class attributes, excluding king and wang, and to achieve random drawing, sorting, shuffling and other functions;

Create a card class

A deck of poker in addition to king wang, the rest of the 52 cards based on the color (clubs, diamonds, spades, hearts) can be divided into 4 groups, each group has 13 cards; So you can create two lists one for suits and one for 13 characters; Using a random combination between two lists to generate 52 cards,

The code is as follows:

import collections Card = collections.namedtuple("Card",['rank','suit']) class FrenchDeck: Ranks = [STR (n) for n in range(2,11)] + list("JQKA") suits = 'spades diamonds clubs hearts'.split() def __init__(self): ranks = [STR (n) for n in range(2,11)] + list("JQKA") suits = 'spades diamonds clubs hearts'.split() def __init__(self):  self._cards = [Card(rank,suit) for suit in self.suits for rank in self.ranks] def __len__(self): Return len(self._cards) def __getitem__(self, position): return self._cards[positionCopy the code

The collections.namedtuple module creates A class to represent A set of cards. [‘ rank’,’suit’] represents the characters (2-10,J-A) and suits in the card, respectively.

Len () returns the number of cards and getitem() gets the specified card under position(index)

Beer_card = Card('7','diamonds') print(beer_card) = FrenchDeck() print('len is -----') Print (len(deck)) print(deck[0]) print(deck[-1]) print(deck[-1]) Len is ----- 52 Card(rank='2', suit='spades') Card(rank='A', suit='hearts') copy codeCopy the code

Draw a card at random

The random module is used to realize the function of random card drawing

Print ("random choice -----------") print(choice(deck)) print(choice(deck)) print(choice(deck)) # Output random choice ----------- Card(rank='8', suit='clubs') Card(rank='5', Suit ='hearts') Card(rank='5', suit='spades') copies the codeCopy the code

List iterates and slices

Because the getitem method hands the [] operation to the self._cards list, the FranckDeck() class can slice and iterate in addition to the index position mentioned above.

Print ('\nslice is --') print(deck[:3]) print('\n iterated ') print('\n iterated ') for deck[:3]: Print (card) print('\n reversed operation ') for card in reversed(deck[:3]): print(card) # Output slice is -- [Card(rank='2', suit='spades'), Card(rank='3', suit='spades'), Card(rank='4', Suit = 'spades)] [Card (rank =' 10 ', suit = 'spades'), the Card (, suit rank =' J '=' spades')] iterative operation Card (rank = '2', Rank ='3', suit='spades') Card(rank='4', suit='spades') Suit ='spades') Card(rank='3', suit='spades') Card(rank='2', suit='spades') copies codeCopy the code

The sorting operation

Generally speaking, when judging the size of A playing card by the number of points, the two is the smallest and the ace is the largest. When creating a list of points in the order mentioned above, you only need to sort the list according to the index of points as a benchmark.

In addition to points, there is also a suit that needs to be considered. For suits, a mapping benchmark (also known as weight) needs to be established, and different suits give different values. Python’s dictionary types meet our needs in many ways

Suit_values = dict(spades = 3, hearts = 2, diamonds = 1, clubs = 0) def spades_high(card): Rank_value = frenchdeck.ranks. Index (card.rank) # rank query return rank_value*len(suit_values) + suit_values[card.suit] # Value print('\nSorted ------------------') # use key = lambda mechanism to sort the list for card in sorted(deck,key = lambda spades_high,reverse= True): print(card) # Output Sorted ------------------ Card(rank='A', suit='spades') Card(rank='A', suit='hearts') Card(rank='A', suit='diamonds') Card(rank='A', suit='clubs') Card(rank='K', suit='spades') Card(rank='K', suit='hearts') Card(rank='K', suit='diamonds') Card(rank='K', Suit ='clubs') Card(rank='Q', suit='spades') Card(rank='Q', suit='hearts') Card(rank='Q', suit='diamonds') duplicates codeCopy the code

Code interpretation:

  • 1, the code uses the dictionary to add a mapping mechanism, spades for 3, hearts for 2, diamonds, followed by clubs;
  • 2. Create spades_high to calculate the total weight of each card;
  • 3. Sorted () function key= spades_high is used as the sorting benchmark to sort cards

shuffling

Shuffle is simply a deck of cards to reorder irregularly; Random. Shuffle can do this fairly well, but only if the object satisfies a mutable protocol, which FranchDeck() does not, and this gives an error:

from random import shuffle print('-------------------\n'*3) deck =FrenchDeck() shuffle(deck) # Output x[i], X [j] = x[j], x[I] TypeError: 'FrenchDeck' object does not support item AssignmentCopy the code

For the above problem, simply change the class from immutable to mutable, creating a function that assigns the setitem property

from random import shuffle print('-------------------\n'*3) def set_deck(deck,position,card): Deck._cards [position] = card deck1 = FrenchDeck() print(deck1[:5]) frenchdeck. __setitem__ = set_deck Card(rank='2', suit='spades') Card(rank='3', suit='spades') Card(rank='4', Rank ='5', suit='spades') Card(rank='6', suit='spades') Card(rank='6', suit='diamonds') Card(rank='4', suit='hearts') Card(rank='Q', suit='diamonds') Card(rank='K', Suit ='clubs') Card(rank='8', suit='spades') copies the codeCopy the code

Here we extract the first 5 elements of the shuffled cards, and have realized the shuffling function!

According to the above code, we can further develop and design 54 visualization pictures of playing cards in advance.

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Create a key:value mapping relationship between playing card characters and visual images, as shown in the following figure. Store this relationship set in a specified database or file, and you can call it directly after using it

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