Passing Mutable Objects

The same object in the memory is referred by both

list_a

and

list_x

Code

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def add_item(list_x):

list_x += [3]

list_a = [1,2]

add_item(list_a)

print(list_a)

PYTHON

Output

[1, 2, 3]

Code

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def add_item(list_x):

list_x = list_x + [3]

list_a = [1,2]

add_item(list_a)

print(list_a)

PYTHON

Output

[1, 2]

Default args are evaluated only once when the function is defined, not each time the function is called.

Code

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def add_item(list_x=[]):

list_x += [3]

print(list_x)

add_item()

add_item([1,2])

add_item()

PYTHON

Output

[3]

[1, 2, 3]

[3, 3]

Built-in functions

Built-in functions are readily available for reuse.

We are already using functions which are pre-defined in Python

• print()
• int()
• str()
• len()

Finding Minimum

min()

returns the smallest item in a sequence or smallest of two or more arguments.

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min(sequence)

min(arg1, arg2, arg3 ...)

PYTHON

Example - 1

Code

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smallest= min(3,5,4)

print(smallest)

PYTHON

Output

3

Example - 2

Code

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smallest = min([1,-2,4,2])

print(smallest)

PYTHON

Output

-2

Minimum of Strings

min(str_1, str_2)

Strings are compared character by character using unicode values.

• P - 80(unicode)

• J - 74(unicode)

Code

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smallest = min("Python", "Java")

print(smallest)

PYTHON

Output

Java

Finding Maximum

max()

returns the largest item in a sequence or largest of two or more arguments.

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max(sequence)

max(arg1, arg2, arg3 ...)

PYTHON

Example - 1

Code

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largest = max(3,5,4)

print(largest)

PYTHON

Ouput

5

Example - 2

Code

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largest = max([1,-2,4,2])

print(largest)

PYTHON

Output

4

Finding Sum

sum(sequence)

returns sum of items in a sequence.

Code

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sum_of_numbers = sum([1,-2,4,2])

print(sum_of_numbers)

PYTHON

Output

5

Ordering List Items

sorted(sequence)

returns a new sequence with all the items in the given sequence ordered in increasing order.

Code

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list_a = [3, 5, 2, 1, 4, 6]

list_x = sorted(list_a)

print(list_x)

PYTHON

Output

[1, 2, 3, 4, 5, 6]

Ordering List Items - Reverse

sorted(sequence, reverse=True)

returns a new sequence with all the items in the given sequence ordered in decreasing order.

Code

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list_a = [3, 5, 2, 1, 4, 6]

list_x = sorted(list_a, reverse=True)

print(list_x)

PYTHON

Output

[6, 5, 4, 3, 2, 1]