- collection of elements with defined order
- flexible: elements can be added, removed, replaced:
d.append('B')
- indexed elements, zero-based:
d[0]
- read more ...
Tuples
- like lists that cannot be changed
- ordered (indexed)
- constant: elements cannot be changed
- collection of unique elements (duplicated values are removed)
- no particular order (no index)
- flexible: elements can be added, removed, replaced:
d.add('B')
- logical operations between sets:
d1.union(d2)
- loop / test:
if 'B' in d:
- a set is like a dictionary with no values
- like sets, but with the possibility to add data to each element:
d['Mike']=('Berlin',1983)
- no particular order (no index)
- elements are unique (key-words)
- flexible: elements and data can be added, removed, replaced
- read more ...
Note...
d={} is an empty dictionary
d={'A'} is a set
d=set() is an empty set
d=() is an empty tuple
d=[] is en empty list
It's a bit confusing.. to check the data type use:
>>> type(d)
<type 'list'>
Convert data type
# check type
>>> mylist = ['A', 'B', 'A']
>>> type(mylist)
<type 'list'>
# convert list to set
>>> myset=set(mylist)
>>> myset
set(['A', 'B'])
>>> type(myset)
<type 'set'>
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