Is it possible to add a key to a Python dictionary after it has been created?
It doesn\'t seem to have an .add()
method.
I feel like consolidating info about Python dictionaries:
data = {}
# OR
data = dict()
data = {'a': 1, 'b': 2, 'c': 3}
# OR
data = dict(a=1, b=2, c=3)
# OR
data = {k: v for k, v in (('a', 1), ('b',2), ('c',3))}
data['a'] = 1 # Updates if 'a' exists, else adds 'a'
# OR
data.update({'a': 1})
# OR
data.update(dict(a=1))
# OR
data.update(a=1)
data.update({'c':3,'d':4}) # Updates 'c' and adds 'd'
The update operator |=
now works for dictionaries:
data |= {'c':3,'d':4}
data3 = {}
data3.update(data) # Modifies data3, not data
data3.update(data2) # Modifies data3, not data2
This uses a new feature called dictionary unpacking.
data = {**data1, **data2, **data3}
The merge operator |
now works for dictionaries:
data = data1 | {'c':3,'d':4}
del data[key] # Removes specific element in a dictionary
data.pop(key) # Removes the key & returns the value
data.clear() # Clears entire dictionary
key in data
for key in data: # Iterates just through the keys, ignoring the values
for key, value in d.items(): # Iterates through the pairs
for key in d.keys(): # Iterates just through key, ignoring the values
for value in d.values(): # Iterates just through value, ignoring the keys
data = dict(zip(list_with_keys, list_with_values))