Menu
To convert a tuple to dictionary in Python, use the dict() method. A dictionary object can be constructed using a dict() function. The dict() function takes a tuple of tuples as an argument and returns the dictionary. Each tuple contains a key-value pair.
A tuple containing a list cannot be used as a key in a dictionary. Answer: True. A list is mutable. Therefore, a tuple containing a list cannot be used as a key in a dictionary.
Answer. Yes, a tuple is a hashable value and can be used as a dictionary key. A tuple would be useful as a key when storing values associated with a grid or some other coordinate type system.
To access the tuple elements from the dictionary and contains them in a list. We have to initialize a dictionary and pass the tuple key and value as an argument. Now to get all tuple keys from the dictionary we have to use the Python list comprehension method.
Try:
>>> t = ((1, 'a'),(2, 'b'))
>>> dict((y, x) for x, y in t)
{'a': 1, 'b': 2}
A slightly simpler method:
>>> t = ((1, 'a'),(2, 'b'))
>>> dict(map(reversed, t))
{'a': 1, 'b': 2}
Even more concise if you are on python 2.7:
>>> t = ((1,'a'),(2,'b'))
>>> {y:x for x,y in t}
{'a':1, 'b':2}
>>> dict([('hi','goodbye')])
{'hi': 'goodbye'}
Or:
>>> [ dict([i]) for i in (('CSCO', 21.14), ('CSCO', 21.14), ('CSCO', 21.14), ('CSCO', 21.14)) ]
[{'CSCO': 21.14}, {'CSCO': 21.14}, {'CSCO': 21.14}, {'CSCO': 21.14}]
If there are multiple values for the same key, the following code will append those values to a list corresponding to their key,
d = dict()
for x,y in t:
if(d.has_key(y)):
d[y].append(x)
else:
d[y] = [x]
Here are couple ways of doing it:
>>> t = ((1, 'a'), (2, 'b'))
>>> # using reversed function
>>> dict(reversed(i) for i in t)
{'a': 1, 'b': 2}
>>> # using slice operator
>>> dict(i[::-1] for i in t)
{'a': 1, 'b': 2}
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With