Python count occurrences of word in file

Given a text file of key-value pairs. The task is to count the number of occurrences of the key-value pairs in the file. The approach is very simple. Maintain another dictionary say d that will store the count of occurrence of each key-value pair of the file. Store the key-value pair of the text file as a key in the dictionary.

Now iterate through the key-value pairs of the file. If the pair is present in the dictionary then increment the value of that pair by one otherwise insert the pair and set its value to one.

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Writing code in comment? Please use ide. Python Main Function Python slice function. Python program to count the. If the key-value pair. Insert the key-value pair. Check out this Author's contributed articles.

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Frequently Asked Python Program 15: Count Occurrences of an element in a list

Don't use this if you want to count multiple items. Calling count in a loop requires a separate pass over the list for every count call, which can be catastrophic for performance. If you want to count all items, or even just multiple items, use Counteras explained in the other answers. Use Counter if you are using Python 2. Counting the occurrences of all items in a list is also known as "tallying" a list, or creating a tally counter.

To count the occurrences of items in l one can simply use a list comprehension and the count method. Alternatively, there's the faster Counter class from the collections library. I checked how much faster Counter is for tallying lists. I tried both methods out with a few values of n and it appears that Counter is faster by a constant factor of approximately 2.

And then there's collections. You can dump any iterable into a Counter, not just a list, and the Counter will retain a data structure of the counts of the elements. Counters are based on Python dictionaries, their keys are the elements, so the keys need to be hashable.

They are basically like sets that allow redundant elements into them. Pandas is a common library, but it's not in the standard library.

Adding it as a requirement is non-trivial. There are builtin solutions for this use-case in the list object itself as well as in the standard library.By using our site, you acknowledge that you have read and understand our Cookie PolicyPrivacy Policyand our Terms of Service.

The dark mode beta is finally here. Change your preferences any time. Stack Overflow for Teams is a private, secure spot for you and your coworkers to find and share information. To get rid of them, open the file using the correct encoding I'm assuming you're on Python 3 :.

Python | Count occurrences of an element in a list

Furthermore, for counting, you can use collections. Counter :. Learn more. Word count from a txt file program Ask Question.

How to Count Word Occurrences in a Text File

Asked 6 years, 3 months ago. Active 5 months ago. Viewed k times. I am counting word of a txt file with the following code:! How can I remove this? Paolo Forgia 5, 6 6 gold badges 32 32 silver badges 51 51 bronze badges. Have a look at string formatting. Active Oldest Votes. Trenton McKinney 5, 13 13 gold badges 20 20 silver badges 35 35 bronze badges. Tim Pietzcker Tim Pietzcker k 53 53 gold badges silver badges bronze badges. David Hoelzer You can check example validity at compileonline.Method 1 Simple approach We keep a counter that keeps on increasing if the esquired element is found in the list.

Method 2 Using count The idea is to use list method count to count number of occurrences. Method 2 Using Counter Counter method returns a dictionary with occurrences of all elements as a key-value pair, where key is the element and value is the number of times that element has occurred.

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Writing code in comment? Please use ide. Given a list in Python and a number x, count number of occurrences of x in the given list. Python code to count the number of occurrences. Recommended Posts: Python Count occurrences of an element in a Tuple Python Count String occurrences in mixed list Python Count the sublists containing given element in a list Python List Element Count with Order Python Count the elements in a list until an element is a Tuple Python Remove all occurrences in nested list Python Count occurrences of a character in string Python Count occurrences of each word in given text file Using dictionary Python program to Count the Number of occurrences of a key-value pair in a text file Python Subtract two list elements if element in first list is greater Python Replace elements in second list with index of same element in first list Python Indices list of matching element from other list Python Slicing list from Kth element to last element Python Insert Nth element to Kth element in other list Python Move one list element to another list.

Chinmoy Lenka. Check out this Author's contributed articles. Load Comments.By using our site, you acknowledge that you have read and understand our Cookie PolicyPrivacy Policyand our Terms of Service.

The dark mode beta is finally here. Change your preferences any time. Stack Overflow for Teams is a private, secure spot for you and your coworkers to find and share information. I am trying to find the count of words that occured in a file.

I have a text file TEST. You're iterating over every line and calling Counter each time. You want Counter to run over the entire file. Learn more. Asked 7 years, 1 month ago. Active 1 year, 1 month ago. Viewed 29k times. Thanks in advance. Mark Tolonen k 14 14 gold badges silver badges bronze badges. Ashwin Ashwin 2 2 gold badges 6 6 silver badges 13 13 bronze badges. Active Oldest Votes.

python count occurrences of word in file

Use the update method of Counter. Mark Tolonen Mark Tolonen k 14 14 gold badges silver badges bronze badges. Mikhail Vladimirov Mikhail Vladimirov Augmented Jacob 1, 16 16 silver badges 43 43 bronze badges. Anorov Anorov 1, 12 12 silver badges 17 17 bronze badges. Anorov What happens if you have a 50gb file that you want to count? Tha just so happens to only have 3 unique words JonClements I was about to say this too, even if here it's unlikely to be the case.

But a best practice is a best practice Yep, you guys are right actually. I was forgetting about the default generator behavior. GrilledTuna GrilledTuna 21 3 3 bronze badges. Making the string to lower.Many times it is required to count the occurrence of each word in a text file. To achieve so, we make use of a dictionary object that stores the word as the key and its count as the corresponding value.

python count occurrences of word in file

We iterate through each word in the file and add it to the dictionary with count as 1. If the word is already present in the dictionary we increment its count by 1. Example 1: First we create a text file of which we want to count the words.

Let this file be sample.

python count occurrences of word in file

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python count occurrences of word in file

Writing code in comment? Please use ide. Open the file in read mode.

Given an item, how can I count its occurrences in a list in Python?

Loop through each line of the file. Remove the leading spaces and newline character. Convert the characters in line to. Split the line into words. Iterate over each word in line. Check if the word is already in dictionary. Increment count of word by 1. Add the word to dictionary with count 1. Print the contents of dictionary. Remove the punctuation marks from the line. Check out this Author's contributed articles.

Load Comments.By using our site, you acknowledge that you have read and understand our Cookie PolicyPrivacy Policyand our Terms of Service. The dark mode beta is finally here. Change your preferences any time. Stack Overflow for Teams is a private, secure spot for you and your coworkers to find and share information. Don't use this if you want to count multiple items. Calling count in a loop requires a separate pass over the list for every count call, which can be catastrophic for performance.

If you want to count all items, or even just multiple items, use Counteras explained in the other answers. Use Counter if you are using Python 2. Counting the occurrences of all items in a list is also known as "tallying" a list, or creating a tally counter.

To count the occurrences of items in l one can simply use a list comprehension and the count method. Alternatively, there's the faster Counter class from the collections library. I checked how much faster Counter is for tallying lists. I tried both methods out with a few values of n and it appears that Counter is faster by a constant factor of approximately 2. And then there's collections.

You can dump any iterable into a Counter, not just a list, and the Counter will retain a data structure of the counts of the elements. Counters are based on Python dictionaries, their keys are the elements, so the keys need to be hashable.

They are basically like sets that allow redundant elements into them. Pandas is a common library, but it's not in the standard library. Adding it as a requirement is non-trivial. There are builtin solutions for this use-case in the list object itself as well as in the standard library. If your project does not already require pandas, it would be foolish to make it a requirement just for this functionality.

I've compared all suggested solutions and a few new ones with perfplot a small project of mine. If you want to count all values at once you can do it very fast using numpy arrays and bincount as follows. Antoher possiblity for getting the count of all elements in the list could be by means of itertools.


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