Array in Python | Set 1 (Introduction and Functions)

Other than some generic containers like list, Python in its definition can also handle containers with specified data types. Array can be handled in python by module named “array“. They can be useful when we have to manipulate only a specific data type values.

Operations on Array :

1. array(data type, value list) :- This function is used to create an array with data type and value list specified in its arguments. Some of the data types are mentioned in the table below.

Type Code	C Type	Python Type	Minimum size in Bytes
‘b’	signed char	int	1
‘B’	unsigned char	int	1
‘u’	Py_UNICODE	unicode character	2
‘h’	signed short	int	2
‘H’	unsigned short	int	2
‘i’	signed int	int	2
‘I’	unsigned int	int	2
‘l’	signed long	int	4
‘L’	unsigned long	int	4
‘q’	signed long long	int	8
‘Q’	unsigned long long	int	8
‘f’	float	float	4
‘d’	double	float	8

2. append() :- This function is used to add the value mentioned in its arguments at the end of the array.

3. insert(i,x) :- This function is used to add the value at the position specified in its argument.

# Python code to demonstrate the working of  
# array(), append(), insert() 
   
# importing "array" for array operations 
import array 
   
# initializing array with array values 
# initializes array with signed integers 
arr = array.array('i', [1, 2, 3])  
  
# printing original array 
print ("The new created array is : ",end=" ") 
for i in range (0, 3): 
    print (arr[i], end=" ") 
  
print("\r") 
  
# using append() to insert new value at end 
arr.append(4); 
  
# printing appended array 
print("The appended array is : ", end="") 
for i in range (0, 4): 
    print (arr[i], end=" ") 
      
# using insert() to insert value at specific position 
# inserts 5 at 2nd position 
arr.insert(2, 5) 
  
print("\r") 
  
# printing array after insertion 
print ("The array after insertion is : ", end="") 
for i in range (0, 5): 
    print (arr[i], end=" ") 

Output:

The new created array is : 1 2 3 
The appended array is : 1 2 3 4 
The array after insertion is : 1 2 5 3 4

4. pop() :- This function removes the element at the position mentioned in its argument, and returns it.

5. remove() :- This function is used to remove the first occurrence of the value mentioned in its arguments.

# Python code to demonstrate the working of  
# pop() and remove() 
   
# importing "array" for array operations 
import array 
   
# initializing array with array values 
# initializes array with signed integers 
arr= array.array('i',[1, 2, 3, 1, 5])  
  
# printing original array 
print ("The new created array is : ",end="") 
for i in range (0,5): 
    print (arr[i],end=" ") 
  
print ("\r") 
  
# using pop() to remove element at 2nd position 
print ("The popped element is : ",end="") 
print (arr.pop(2)); 
  
# printing array after popping 
print ("The array after popping is : ",end="") 
for i in range (0,4): 
    print (arr[i],end=" ") 
  
print("\r") 
  
# using remove() to remove 1st occurrence of 1 
arr.remove(1) 
  
# printing array after removing 
print ("The array after removing is : ",end="") 
for i in range (0,3): 
    print (arr[i],end=" ") 

Output:

The new created array is : 1 2 3 1 5 
The popped element is : 3
The array after popping is : 1 2 1 5 
The array after removing is : 2 1 5

6. index() :- This function returns the index of the first occurrence of value mentioned in arguments.

7. reverse() :- This function reverses the array.

# Python code to demonstrate the working of  
# index() and reverse() 
   
# importing "array" for array operations 
import array 
   
# initializing array with array values 
# initializes array with signed integers 
arr= array.array('i',[1, 2, 3, 1, 2, 5])  
  
# printing original array 
print ("The new created array is : ",end="") 
for i in range (0,6): 
    print (arr[i],end=" ") 
  
print ("\r") 
  
# using index() to print index of 1st occurrenece of 2 
print ("The index of 1st occurrence of 2 is : ",end="") 
print (arr.index(2)) 
  
#using reverse() to reverse the array 
arr.reverse() 
  
# printing array after reversing 
print ("The array after reversing is : ",end="") 
for i in range (0,6): 
    print (arr[i],end=" ") 

Output:

The new created array is : 1 2 3 1 2 5 
The index of 1st occurrence of 2 is : 1
The array after reversing is : 5 2 1 3 2 1

Reference :
https://docs.python.org/3/library/array.html#module-array

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