Tuples

Support all operations for Sequences
Immutable, but member objects may be mutable
If the contents of a list shouldn't chance, use a tuple to prevent items for accidently being added, changed or deleted
Tuples are more efficient than lists due to Python's implementation



In [1]:

    
x = () # no-item tuple



In [2]:

    
len(x)









    Out[2]:





0



In [3]:

    
type(x)









    Out[3]:





tuple



In [4]:

    
y = (1,2,3) # three items



In [5]:

    
y[2]









    Out[5]:





3



In [6]:

    
y[-1]









    Out[6]:





3



In [7]:

    
y[0]









    Out[7]:





1



In [8]:

    
type(y)









    Out[8]:





tuple



In [9]:

    
z = 2, # single-item tuple



In [10]:

    
z









    Out[10]:





(2,)



In [11]:

    
len(z)









    Out[11]:





1



In [12]:

    
list1 = [10, 20, 30]



In [13]:

    
a = tuple(list1) # tuple from list
a









    Out[13]:





(10, 20, 30)

And YES, they are IMMUTABLE! Watch it:



In [14]:

    
a









    Out[14]:





(10, 20, 30)



In [15]:

    
del(a[0])









    



---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-15-49f046f2d244> in <module>()
----> 1 del(a[0])

TypeError: 'tuple' object doesn't support item deletion



In [16]:

    
a[0] = 11









    



---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-16-63bb5f4f24d7> in <module>()
----> 1 a[0] = 11

TypeError: 'tuple' object does not support item assignment



In [17]:

    
a[0]









    Out[17]:





10

But, in the case, a list inside a tuple...



In [18]:

    
a = ([1, 2], 3)



In [19]:

    
a









    Out[19]:





([1, 2], 3)



In [20]:

    
del(a[0][1]) # a[0][1] is the 1



In [21]:

    
a









    Out[21]:





([1], 3)



In [22]:

    
t = 12345, 54321, 'tuple!'



In [23]:

    
t









    Out[23]:





(12345, 54321, 'tuple!')



In [24]:

    
# tuples may be nested
c = a, (1, 2, 3, 4)
c









    Out[24]:





(([1], 3), (1, 2, 3, 4))



In [25]:

    
t = 'abc', 1000, 3.14



In [26]:

    
x, y, z = t # tuple packing
x









    Out[26]:





'abc'



In [32]:

    
t1 = (10, 20, 30, 100, 1000, 10, 20, 20)



In [33]:

    
t1.count(10)









    Out[33]:





2



In [34]:

    
t1.count(20)









    Out[34]:





3



In [35]:

    
t1.index(10)









    Out[35]:





0



In [36]:

    
t1.index(100)









    Out[36]:





3



In [37]:

    
100 in t1









    Out[37]:





True



In [38]:

    
3 in t1









    Out[38]:





False



In [39]:

    
3 not in t1









    Out[39]:





True



In [40]:

    
for name in ('John', 'Mary'):
    print('Hello', name)









    



Hello John
Hello Mary



In [45]:

    
max(t1)









    Out[45]:





1000



In [46]:

    
min(t1)









    Out[46]:





10



In [47]:

    
sorted(t1) # return a new sorted list, does not sorte the tuple itself! Remember: immutable!









    Out[47]:





[10, 10, 20, 20, 20, 30, 100, 1000]



In [48]:

    
t1









    Out[48]:





(10, 20, 30, 100, 1000, 10, 20, 20)



In [49]:

    
sum(t1)









    Out[49]:





1210



In [ ]: