a = (1)
type(a)

a = (1,)
type(a)

from collections import namedtuple

MyHost = namedtuple('MyHost',['host', 'ip'])
MyHost

MyHost(host='cn', ip='1.2.3.4')

[ MyHost._make(h) for h in Hosts ]

from ast import literal_eval as make_tuple
make_tuple('(1,2)')

[1,]

list(map(lambda x: x*2, [1,2,3]))

sorted(['ad','abd','b'])

sorted({'ad','abd','b','b'})

a1 = ["live", "arp", "strong"] 
a2 = ["lively", "alive", "harp", "sharp", "armstrong"]
[s1 for s1 in a1 for s2 in a2 if s1 in s2]

students = [('john', 'A', 15), ('jane', 'B', 12), ('dave', 'B', 10),]  
sorted(students, key=lambda s : s[2])   # sort by age  

[1,2,3][::-1]

lst1 = [1, 2, 3, 4, 1, 4, 1]
print( [ {i: lst1.count(i)} for i in set(lst1) ] )

from collections import Counter
c = Counter(lst1)
c

c.most_common()

delete_nth = lambda order, max_e: [x for i, x in enumerate(order) if order[:i].count(x) < max_e]
delete_nth([20,37,20,21],1)  #item appears at most 1 times

a = [1,2,3,2,1]
a.remove(1) #insert, remove or sort only modify the list have no return value printed
a.insert(2, -1) # 2 is index, -1 is value
b = [1,2,3,2,1]
b.pop(1) # 1 is index
print(a)
a.reverse()
print(a)
print(b)
a+b

{x for x in range(8)} # set

{1,3,2} - {1}

{1,3,2} & {1}

{1,3,2} | {1, 4}

print(1 ^ 1, 0 ^ 0, 1 ^ 0, 0 ^ 1)

{1,3,2} ^ {1, 4} # not in both

a = {'i': 30,'u': 20,'she':44}
b = {'i': 31,'u': 21,'he': 55}
c = a.copy()
c.update(b)
c

from collections import defaultdict
d = defaultdict(list)
d[1] = 3 # int, not default list
d[1] = [4]
d[1].append(5)
d[2]  #set to default []
d

i = defaultdict(int)
i[1]

from collections import OrderedDict
d = {1:'a', 3:'c', 2:"b"}
d

OrderedDict(d)

d[3]