Counter():
The Counter class is a subset of the object data-set offered by Python3’s collections module. The Collections module exposes specialized container datatypes to the user, serving as an alternative to Python’s general-purpose built-ins such as dictionaries, lists, and tuples.
The counter is a subclass that counts hashable objects. When called, it constructs an iterable hash table implicitly.
elements() is a function of the Counter class that, when called on a Counter object, returns an itertool of all the known elements in the Counter object.
Parameters:
It does not accept any parameters.
Return type:
Returns an itertool for every element in the Counter object with a positive count.
Exceptions and Errors:
Because it returns an itertool rather than a specific data-container, it will output a garbage value when directly printed. -> If an item's count has already been established in the Counter object, it will ignore items with zero and negative values.
Examples:
Example1:
Input:
Given String = "python-programs"
Output:
p = 2 y = 1 t = 1 h = 1 o = 2 n = 1 - = 1 r = 2 g = 1 a = 1 m = 1 s = 1
Example2:
Input:
Given List=Â [3, 1, 3, 4, 5, 6, 2, 2, 1, 5, 6, 9]
Output:
3 = 2 1 = 2 4 = 1 5 = 2 6 = 2 2 = 2 9 = 1
Collections Counter() Method with Examples in Python
Method #1: Using Built-in Functions (Static Input)
i)elements() for string
Approach:
- Import the Counter function from collections using the import keyword.
- Give the string as static input and store it in a variable.
- Apply the Counter() function for the string and store it in a variable(It returns a dictionary).
- Apply elements() function for the Above result Counter Dictionary elements and print it.
- The Exit of the Program.
Below is the implementation:
# Import the Counter function from collections using the import keyword. from collections import Counter # Give the string as static input and store it in a variable. gvnstrng = "python-programs" # Apply the Counter() function for the string and store it in a # variable(It returns a dictionary). rslt = Counter(gvnstrng) # Apply elements() function for the Above result Counter Dictionary elements and print it. print(rslt.elements())
Output:
<itertools.chain object at 0x7f8599afb780>
ii)Printing elements of Counter(String)
Approach:
- Import the Counter function from collections using the import keyword.
- Give the string as static input and store it in a variable.
- Apply the Counter() function for the string and store it in a variable(It returns a dictionary).
- Loop in the elements of the Above result Counter Dictionary elements using for loop and elements() function.
- Print the elements.
- The Exit of the Program.
Below is the implementation:
# Import the Counter function from collections using the import keyword.
from collections import Counter
# Give the string as static input and store it in a variable.
gvnstrng = "python-programs"
# Apply the Counter() function for the string and store it in a
# variable(It returns a dictionary).
rslt = Counter(gvnstrng)
# Loop in the elements of the Above result Counter Dictionary elements using for loop and elements() function.
for element in rslt.elements():
# Print the elements.
print(element)
Output:
p p y t h o o n - r r g a m s
iii)Printing elements with corresponding Frequency using elements()(String)
Approach:
- Import the Counter function from collections using the import keyword.
- Give the string as static input and store it in a variable.
- Apply the Counter() function for the string and store it in a variable(It returns a dictionary).
- Loop in the elements of the Above result Counter Dictionary elements using for loop and elements() function.
- Print the elements and their frequency using the [] operator.
- The Exit of the Program.
Below is the implementation:
# Import the Counter function from collections using the import keyword.
from collections import Counter
# Give the string as static input and store it in a variable.
gvnstrng = "python-programs"
# Apply the Counter() function for the string and store it in a
# variable(It returns a dictionary).
rslt = Counter(gvnstrng)
# Loop in the elements of the Above result Counter Dictionary elements using for loop and elements() function.
for element in rslt.elements():
# Print the elements and their frequency using the [] operator.
print(element, ' = ', rslt[element])
Output:
p = 2 p = 2 y = 1 t = 1 h = 1 o = 2 o = 2 n = 1 - = 1 r = 2 r = 2 g = 1 a = 1 m = 1 s = 1
iv)Printing elements with corresponding Frequency(List)
Approach:
- Import the Counter function from collections using the import keyword.
- Give the list as static input and store it in a variable.
- Apply the Counter() function for the list and store it in a variable(It returns a dictionary).
- Loop in the elements of the Above result Counter Dictionary elements using for loop .
- Print the elements and their frequency using the [] operator.
- The Exit of the Program.
Below is the implementation:
# Import the Counter function from collections using the import keyword.
from collections import Counter
# Give the list as static input and store it in a variable.
gvllst = [3, 1, 3, 4, 5, 6, 2, 2, 1, 5, 6, 9]
# Apply the Counter() function for the list and store it in a
# variable(It returns a dictionary).
rslt = Counter(gvllst)
# Loop in the Above result Counter Dictionary elements using for loop.
for element in rslt:
# Print the elements and their frequency using the [] operator.
print(element, ' = ', rslt[element])
Output:
3 = 2 1 = 2 4 = 1 5 = 2 6 = 2 2 = 2 9 = 1
v)Printing elements with corresponding frequency(String)
Approach:
- Import the Counter function from collections using the import keyword.
- Give the string as static input and store it in a variable.
- Apply the Counter() function for the string and store it in a variable(It returns a dictionary).
- Loop in the elements of the Above result Counter Dictionary elements using for loop.
- Print the elements and their frequency using the [] operator.
- The Exit of the Program.
Below is the implementation:
# Import the Counter function from collections using the import keyword.
from collections import Counter
# Give the string as static input and store it in a variable.
gvnstrng = "python-programs"
# Apply the Counter() function for the string and store it in a
# variable(It returns a dictionary).
rslt = Counter(gvnstrng)
# Loop in the elements of the Above result Counter Dictionary elements using for loop and elements() function.
for element in rslt:
# Print the elements and their frequency using the [] operator.
print(element, ' = ', rslt[element])Output:
p = 2 y = 1 t = 1 h = 1 o = 2 n = 1 - = 1 r = 2 g = 1 a = 1 m = 1 s = 1
Method #2: Using Built-in Functions (User Input)
Approach:
- Import the Counter function from collections using the import keyword.
- Give the list as user input using map(),list(),input(),int() functions and store it in a variable.
- Apply the Counter() function for the list and store it in a variable(It returns a dictionary).
- Loop in the elements of the Above result Counter Dictionary elements using for loop .
- Print the elements and their frequency using the [] operator.
- The Exit of the Program.
Below is the implementation:
# Import the Counter function from collections using the import keyword.
from collections import Counter
# Give the list as user input using map(),list(),input(),int() functions and store it in a variable.
gvllst = list(map(int, input('Enter some random elements = ').split()))
# Apply the Counter() function for the list and store it in a
# variable(It returns a dictionary).
rslt=Counter(gvllst)
# Loop in the Above result Counter Dictionary elements using for loop and elements() function.
for element in rslt:
# Print the elements and their frequency using the [] operator.
print(element, ' = ', rslt[element])
Output:
Enter some random elements = 7 1 2 1 8 9 2 4 6 7 = 1 1 = 2 2 = 2 8 = 1 9 = 1 4 = 1 6 = 1