How do you create a count function in python?

The count[] is a built-in function in Python. It will return the total count of a given element in a string. The counting begins from the start of the string till the end. It is also possible to specify the start and end index from where you want the search to begin.

In this Python tutorial, you will learn:

  • Python count
  • The syntax for PythonString Count[]
  • Example 1: Count Method on a String
  • Example 2: Count occurrence of a character in a given string
  • Example 3: Count occurrence of substring in a given string

The syntax for PythonString Count[]

Python count function syntax:

string.count[char or substring, start, end]

Parameters of Python Syntax

  • Char or substring: You can specify a single character or substring you are wants to search in the given string. It will return you the count of the character or substring in the given string.
  • start : [optional] It indicates the start index from where the search will begin. If not given, it will start from 0. For example, you want to search for a character from the middle of the string. You can give the start value to your count function.
  • end: [optional] It indicates the end index where the search ends. If not given, it will search till the end of the list or string given. For example, you don’t want to scan the entire string and limit the search till a specific point you can give the value to end in your count function, and the count will take care of searching till that point.

ReturnValue

The count[] method will return an integer value, i.e., the count of the given element from the given string. It returns a 0 if the value is not found in the given string.

Example 1: Count Method on a String

The following example shows the working of count[] function on a string.

str1 = "Hello World"
str_count1 = str1.count['o']  # counting the character “o” in the givenstring
print["The count of 'o' is", str_count1]

str_count2 = str1.count['o', 0,5]
print["The count of 'o' usingstart/end is", str_count2]

Output:

The count of 'o' is 2
The count of 'o' usingstart/end is 1

Example 2: Count occurrence of a character in a given string

The following example shows the occurrence of a character in a given string as well as in by using the start/end index.

str1 = "Welcome to Guru99 Tutorials!"
str_count1 = str1.count['u']  # counting the character “u” in the given string
print["The count of 'u' is", str_count1]

str_count2 = str1.count['u', 6,15]
print["The count of 'u' usingstart/end is", str_count2]

Output:

The count of 'u' is 3
The count of 'u' usingstart/end is 2

Example 3: Count occurrence of substring in a given string

Following example shows the occurrence of substring in a givenstring as well as usingstart/endindex.

str1 = "Welcome to Guru99 - Free Training Tutorials and Videos for IT Courses"
str_count1 = str1.count['to'] # counting the substring “to” in the givenstring
print["The count of 'to' is", str_count1]
str_count2 = str1.count['to', 6,15]
print["The count of 'to' usingstart/end is", str_count2]

Output:

The count of 'to' is 2
The count of 'to' usingstart/end is 1

Summary:

  • The count[] is a built-in function in Python. It will return you the count of a given element in a list or a string.
  • In the case of a string, the counting begins from the start of the string till the end. It is also possible to specify the start and end index from where you want the search to begin.
  • The count[] method returns an integer value.

The count[] method is one of the inbuilt functions in Python. As the name implies, it returns the number of times a specified value appears in a string or a list.

In real-time, we deal with statistical functions and financial functions where the number of arguments contains numbers and the number of cells contains numbers too. Hence, the count method helps us immensely.

This method is also used to count numbers in the given set of arrays.

There are two types of methods for ‘count’ in Python. They are as follows:

  1. String count[] method
  2. List count[] method

PYTHON String Count[] Method:

The count [] is used to count the number of times a substring occurs in each string. A single parameter [substring value] is quite enough for execution, optionally the other two values are also available.

Syntax:

string.count[value, start, end]

or

string.count[value]

Parameter values:

Value - This is the substring whose count in Python is to be found. This can be a single character or a substring, which needs to be searched for in the given string.

Start [Optional] - This should be an integer, which is the index value to start the search in the given string. By default, it starts from 0, when the value is not given.

End [Optional] - This should be an integer, which is the index value to end the search. By default, it is the end of the string. When the end value is not given, it will find values until the end of the string or list.

The count in Python method returns a number as a return value. The integer value is the return value. When the count in Python returns 0, then it means that the value is not found in the list or string.

Example 1: 

Code 1:

# this line for declaring a variable and its value

myText = "I love Paris, Paris is my favorite tourist destination"

# this line for calling the count method

numofCounts = myText.count["Paris"]

# this line for print output

print["{} number of times".format[numofCounts]] # format is the inbuilt 

function to use join the values.

Output:

2 number of times

In the above example, the count method will search for the word “Paris'' in myText. It will return 2 as an integer value since the word Paris occurs two times in the string. The variable ‘numofCounts’ will get the return value and display the result.

Example 2:

Code 2:

# this line for declaring the variable and its value

myText = "I love Paris, Paris is my favorite tourist destination"

# this line for calling the count method with start and end value

numofCounts = myText.count["Paris",8,20] # 8 is start value , 20 is end value

# this line for print output

print["{} number of times".format[numofCounts]] 

# format is the inbuilt function to use join the values.

Output

1 number of times

In the above example, the same count method searches for the word “Paris” from the specified index value. Here, the count method has two more parameters. The starting search point is the 8th index, and it ends the searching at the 20th index value of myText string [“aris, Paris is”]. So, it returns only 1 time.

PYTHON List Count[] method:

The count[] method returns the number of elements that appear in the specified list. This method takes a single argument as input. It iterates the list and counts the number of instances that match it.

Syntax:

list.count[value]

Parameters:

Value—The value to be counted in Python. It can be of any type [String, number, list, etc.]

Example 1:

Code 3:

# this line for declare variable and its value

cities= ["Paris","London","New York"]

# this line for calling count method

numofCount =cities.count["Paris"] # this is for test data Paris already Exist

numofTestCount  =  cities.count["Rome"] # this is for test data Rome not exist in list

# this line for print output

print["{} number of times".format[numofCount]] # one because paris exist in List

print["{} number of times".format[numofTestCount]] # zero because Rome not exist in List

Output

1 number of times

0 number of times

Note that in the above example, the print numofTestCount output is 0, as it received an invalid or non-existent parameter.

Example 2:

Count from even number list:

Code 4:

# this line for declaring the variable and its value

evennumbers= [2,4,6,8,10,12,14,16,18,20,22]

# this line for calling the count method

numofEvens = evennumbers.count[4]

print["{} number of times".format[numofEvens]] # format is the inbuilt function to use join the values.

Output

1 number of times

You might have noticed that the output of print numofEvens was 1, though 2 appears at 12 and 20 in the list. It is because the list only counts the element which matches the data type and the value of the parameter passed.

Example 3:

Count from tuple 

Code 5:

# this line for declare variable and its value

cities = [['Paris',1],['London',2],['Rome',3]] # here we passing Tuple values

numofCounts = cities.count[['London',2]]# here we pass only one tuble value . if we pass more tuple values we will face Type Error

print["{} number of times".format[numofCounts]] # format is the in-build function to use join the values.

Output

1 number of times

In the above example, cities denote the list variable that holds a few tuple values. We can find the tuple value with the help of the count method in the list. The numofCounts variable displays 1 since the value was found one time.

When we deal with the list count method, the error possibility in the count method is TypeError. When over 1 parameter is passed, it throws TypeError.

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Conclusion:

Count[] is a Python built-in function that returns the number of times an object appears in a list. The count[] method is one of Python's built-in functions. It returns the number of times a given value occurs in a string or a list, as the name implies. In real-time, we deal with statistical functions and financial functions where the number of arguments containing numbers, or the number of cells containing a number, will benefit from the count process. This approach can also be used to count the number of elements in an array.

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Is there a count function in Python?

Count[] is a Python built-in function that returns the number of times an object appears in a list. The count[] method is one of Python's built-in functions. It returns the number of times a given value occurs in a string or a list, as the name implies.

How do you add a count in Python?

Python List count[].
Syntax of List count[] The syntax of the count[] method is: list.count[element].
count[] Parameters. The count[] method takes a single argument:.
Return value from count[] ... .
Example 1: Use of count[] ... .
Example 2: Count Tuple and List Elements Inside List..

How do you run a count in Python?

The count[] is a built-in function in Python. It will return the total count of a given element in a string. The counting begins from the start of the string till the end. It is also possible to specify the start and end index from where you want the search to begin.

What is list count function in Python?

Python List count[] method returns the count of how many times a given object occurs in a List.

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