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.

Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above.