Array in Python | Set 2 (Important Functions)

Array in Python | Set 1 (Introduction and Functions)

Below are some more functions.

1. typecode :- This function returns the data type by which array is initialised.

2. itemsize :- This function returns size in bytes of a single array element.

3. buffer_info() :- Returns a tuple representing the address in which array is stored and number of elements in it.

# Python code to demonstrate the working of  
# typecode, itemsize, buffer_info() 
   
# 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])  
  
# using typecode to print datatype of array 
print ("The datatype of array is : ") 
print (arr.typecode) 
  
# using itemsize to print itemsize of array 
print ("The itemsize of array is : ") 
print (arr.itemsize) 
  
# using buffer_info() to print buffer info. of array 
print ("The buffer info. of array is : ") 
print (arr.buffer_info()) 

Output:

The datatype of array is : 
i
The itemsize of array is : 
4
The buffer info. of array is : 
(29784224, 6)

Instead of import array, we can also use * to import array.

# importing "array" using * for array operations 
from array import *
   
# initializing array with array values 
# initializes array with signed integers 
arr = array('i',[1, 2, 3, 1, 2, 5])  
  
print(arr) 

Output:

array('i', [1, 2, 3, 1, 2, 5])

4. count() :- This function counts the number of occurrences of argument mentioned in array.

5. extend(arr) :- This function appends a whole array mentioned in its arguments to the specified array.

# Python code to demonstrate the working of  
# count() and extend() 
   
# importing "array" for array operations 
import array 
   
# initializing array 1 with array values 
# initializes array with signed integers 
arr1 = array.array('i',[1, 2, 3, 1, 2, 5])  
  
# initializing array 2 with array values 
# initializes array with signed integers 
arr2 = array.array('i',[1, 2, 3])  
  
# using count() to count occurrences of 1 in array 
print ("The occurrences of 1 in array is : ") 
print (arr1.count(1)) 
  
# using extend() to add array 2 elements to array 1  
arr1.extend(arr2) 
  
print ("The modified array is : ") 
for i in range (0,9): 
    print (arr1[i]) 

Output:

The occurrences of 1 in array is : 
2
The modified array is : 
1
2
3
1
2
5
1
2
3

6. fromlist(list) :- This function is used to append a list mentioned in its argument to end of array.

7. tolist() :- This function is used to transform an array into a list.

# Python code to demonstrate the working of  
# fromlist() and tolist() 
   
# 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])  
  
# initializing list 
li = [1, 2, 3] 
  
# using fromlist() to append list at end of array 
arr.fromlist(li) 
  
# printing the modified array 
print ("The modified array is : ",end="") 
for i in range (0,9): 
    print (arr[i],end=" ") 
  
# using tolist() to convert array into list 
li2 = arr.tolist() 
  
print ("\r") 
  
# printing the new list 
print ("The new list created is : ",end="") 
for i in range (0,len(li2)): 
    print (li2[i],end=" ") 

Output:

The modified array is : 1 2 3 1 2 5 1 2 3 
The new list created is : 1 2 3 1 2 5 1 2 3

This article is contributed by Manjeet Singh. If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.

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