collection of elements with defined order
flexible: elements can be added, removed, replaced: d.append('B')
indexed elements, zero-based: d[0]
mylist = ['Antje', 'Mike', 'Michel']
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
similar to sets (unique, no order), but with the possibility to add data to each entry
no particular order (no index)
elements are unique (key identifier)
flexible: elements and data can be added, removed, replaced
d['Antje']=('Barcelona',1987)
→ Standard single key dictionaries
d['Antje']['year']=1987
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
To check the data type use:
type(d)
<type 'list'>
# check type
mylist = ['A', 'B', 'A']
type(mylist)
<type 'list'>
# convert list to set
myset=set(mylist)
set(['A', 'B'])
type(myset)
<type 'set'>
# convert text-string into single element list (without split into characters)
s = 'filename.txt'
myFileList = [s]
['filename.txt']
"if, else" data type testing
x = ['A', 'B']
if type(x) is list:
print('YES, x is a list')
else:
print('NO, x is not a list')
YES, x is a list