Using the function Map, count the number of words that start with ‘S’ in list in Python3

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I'd like to get the total count of elements in a list starting with 'S' by only using Map function and Lambda expression. What I've tried is using list function encapsulated which is not I want. Below is my code in which I've tried which is not desired.

input_list = ['San Jose', 'San Francisco', 'Santa Fe', 'Houston']
desireList = list(map(lambda x: x if x[0] == 'S' else '', input_list))
desireList.remove('')
print(len(desireList))

It's more Pythonic to use sum with a generator expression for your purpose:

sum(w.startswith('S') for w in input_list)

or:

sum(f == 'S' for f, *_ in input_list)

or if you still would prefer to use map and lambda:

sum(map(lambda x: x[0] == 'S', input_list))

With your sample input, all of the above would return: 3

Creating a program in python that counts the number of words in a , I'd like to get the total count of elements in a list starting with 'S' by only using Map function and Lambda expression. What I've tried is using list� map_name.count(key k) Parameters: The function accepts a mandatory parameter k which specifies the key to be searched in the map container. Return Value: The function returns the number of times the key K is present in the map container. It returns 1 if the key is present in the container as the map only contains a unique key.

Here's an alternate approach

list( map( lambda x : x[0].lower() , input_list ) ).count('s')

Generate a list of 1st characters per item in the list, and count the number of 's' characters in that list.

map count() function in C++ STL, Value of words will be the method for splitting strings. Maybe that is not what you want. python - example - using the function map, count the number of words that start with ‘s’ in input_list. Using python map and other functional tools (6)

You can try this:

count = list(map(lambda x:x[0]=='S',input_list)).count(True)

Count the number of words with given prefix using Trie , The map::count() is a built-in function in C++ STL which returns 1 if the element Return Value: The function returns the number of times the key K is present in the Count substrings that contain all vowels | SET 2 � Count numbers having 0 as a you can also write an article using contribute.geeksforgeeks.org or mail your� Searches the container for elements with a key equivalent to k and returns the number of matches. Because all elements in a map container are unique, the function can only return 1 (if the element is found) or zero (otherwise).

Counting Word Frequencies with Python, The task is to count the number of words in list of string with given prefix using trie . Examples: children: This field is used for mapping from a character to the next level trie node Function to create New Trie Node Construct trie containing. Related Formulas. count specific words in a cell or a range If you want to count the number of a specific word in a single cell, you need to use the SUBSTITUTE function to remove all that certain word in text string, then using LEN function to calculate the length of the substring that without that specific word.…

1. Language Processing and Python, So we're going to filter out the common function words. Copy it and put it at the beginning of the obo.py library that you are building. 'among'] stopwords += [' amongst', 'amoungst', 'amount', Now getting rid of the stop words in a list is as easy as using another list comprehension. C Program to Count Total Number of Words in a String Example 1. This program allows the user to enter a string (or character array), and a character value. Next, it will count the total number of words present inside this string using For Loop.

PySpark – Word Count Example, Once you've installed NLTK, start up the Python interpreter as before, and In this section we will see how to use the computer to count the words in a text in a When we count the number of tokens in a text, say, the phrase to be or not to be, The block of code that does a task for us is called a function, and we define a� count() is an inbuilt function in Python that returns count of how many times a given object occurs in list. Syntax : list_name.count(object) Parameters : Object is the things whose count is to be returned.

Comments
  • It might not be strictly necessary, but the asker did specify that they were looking for a solution using map.
  • Indeed. I've updated my answer with a solution that uses map and lambda then.
  • Yes, this is what I expected. Thank You.
  • The lambda function returns a Boolean value as returned by the == operator, and the map generator maps the list items to the lambda so it outputs a sequence of Boolean values, or integers of 0s and 1s, which sum can then add up.
  • I'd also like to know as I'm new to Python. How to extract the data from map function. Like I've explored using set function to extract data.