Predict the output of cells 4, 8, and 12.



In [1]:

    
a = [i*i for i in range(3)]
a









    Out[1]:





[0, 1, 4]



In [2]:

    
b = a



In [3]:

    
b[1] = 'hello'
b









    Out[3]:





[0, 'hello', 4]



In [4]:

    
a









    Out[4]:





[0, 'hello', 4]



In [5]:

    
a = [i*i for i in range(3)]
a









    Out[5]:





[0, 1, 4]



In [6]:

    
b = a[:]



In [7]:

    
b[1] = 'hello'
b









    Out[7]:





[0, 'hello', 4]



In [8]:

    
a









    Out[8]:





[0, 1, 4]



In [9]:

    
a = [i*i for i in range(3)]
a









    Out[9]:





[0, 1, 4]



In [10]:

    
b = a.copy()



In [11]:

    
b[1] = 'hello'
b









    Out[11]:





[0, 'hello', 4]



In [12]:

    
a









    Out[12]:





[0, 1, 4]

Show what map() does.



In [13]:

    
def foo(s):
    return s + ' on the Beach.'

list(map(foo, ('sand', 'clams', 'dunes')))









    Out[13]:





['sand on the Beach.', 'clams on the Beach.', 'dunes on the Beach.']



In [14]:

    
a = (1, 2, 3)
b = (2, 3, 4, 5)

from itertools import zip_longest

sum(map(sum, zip_longest(a, b, fillvalue=0)))









    Out[14]:





20



In [15]:

    
sum((sum(a), sum(b)))









    Out[15]:





20



In [16]:

    
sum(a + b)









    Out[16]:





20

fstrings can handle expressions, not just variable names.



In [17]:

    
f'hello {sum(map(sum, zip_longest(a, b, fillvalue=0)))} world'









    Out[17]:





'hello 20 world'