How do you filter a text string in python?
I am running through text and I want to save the items that do not contain certain text. Show
The text consists of single words, and multiple words. so far i have:
and the error i get it:
In the above filter bigrams does not work. Please help? Thanks asked Dec 14, 2017 at 7:30
4 You can use this solution. You don't have to iterate over
answered Dec 14, 2017 at 7:50
Sohaib FarooqiSohaib Farooqi 5,1173 gold badges29 silver badges41 bronze badges I assume for bigrams you are just interested if both words is in "text" or not, and not concerned with their order. This will work:-
Note:- In filter biagrams i have changed ticket to tickets, otherwise it won't work for "mytext" answered Dec 14, 2017 at 8:22
MukuMuku 5183 silver badges17 bronze badges 1 In this article we will discuss when & how to use python’s filter() function with lambda Python provides a method to filter out contents from a given sequence that can be a list, string or tuple etc. Arguments: Returns: Logic: Let’s
understand by examples Advertisements Suppose we have a list of strings i.e. Now let’s filter the contents of list and keep the strings with length 2 only using filter() i.e. Output: So, filter() iterated over all the strings in given list and the called isOfLengthFour() for each string element. String elements for which
isOfLengthFour() returned True were kept in a separate sequence and returned. Using filter() with Lambda functionAs you can see that we have created a separate function isOfLengthFour() and passed it to filter() function. We can completely avoid the creation of these kind of one time small function by using lambda function. filteredList = list(filter(lambda x : len(x) == 2 , listOfStr)) print('Filtered List : ', filteredList) Output: Filtered List : ['hi', 'is', 'us'] It worked same as the previous example but we avoided creating extra function by using a lambda function. Filter characters from a string in Python using filter()We can also use filter() with a string as an iterable sequence and can filter out characters from it. Suppose we have a string i.e. strObj = 'Hi this is a sample string, a very sample string' Now let’s use filter() to remove or filter all occurrences of characters ‘s’ and ‘a’ from the above string i.e. filteredChars = ''.join((filter(lambda x: x not in ['a', 's'], strObj))) print('Filtered Characters : ', filteredChars) Output: Filtered Characters : Hi thi i mple tring, very mple tring filter() basically returned a list of characters from above string by filtered all occurrences of ‘s’ & ‘a’. Then by using join() we joined the filtered list of characters to a single string. Filter an array in Python using filter()Suppose we have two array i.e. array1 = [1,3,4,5,21,33,45,66,77,88,99,5,3,32,55,66,77,22,3,4,5] array2 = [5,3,66] Now we want to filter the contents in array1 i.e. by removing numbers from array1 which are common in array1 and array2. For example new array should be, [1, 4, 21, 33, 45, 77, 88, 99, 32, 55, 77, 22, 4] Now let’s see how to do that using filter() and lambda function filteredArray = list(filter(lambda x : x not in array2, array1)) print('Filtered Array : ', filteredArray) Output: Filtered Array : [1, 4, 21, 33, 45, 77, 88, 99, 32, 55, 77, 22, 4] It basically filtered out the elements from array1 which were present in array2. Complete example is as follows, ''' Check if given string's length is 2 ''' def isOfLengthFour(strObj): if len(strObj) == 2: return True else: return False def main(): # List of string listOfStr = ['hi', 'this' , 'is', 'a', 'very', 'simple', 'string' , 'for', 'us'] print('Original List : ', listOfStr) print('*** Filter list using filter() and a function ***') filteredList = list(filter(isOfLengthFour , listOfStr)) print('Filtered List : ', filteredList) print('*** Filter list using filter() and a Lambda Function ***') filteredList = list(filter(lambda x : len(x) == 2 , listOfStr)) print('Filtered List : ', filteredList) print('*** Filter characters from a string using filter() ***') strObj = 'Hi this is a sample string, a very sample string' filteredChars = ''.join((filter(lambda x: x not in ['a', 's'], strObj))) print('Filtered Characters : ', filteredChars) print('*** Filter an array in Python using filter() ***') array1 = [1,3,4,5,21,33,45,66,77,88,99,5,3,32,55,66,77,22,3,4,5] array2 = [5,3,66] filteredArray = list(filter(lambda x : x not in array2, array1)) print('Filtered Array : ', filteredArray) if __name__ == '__main__': main() Output: Original List : ['hi', 'this', 'is', 'a', 'very', 'simple', 'string', 'for', 'us'] *** Filter list using filter() and a function *** Filtered List : ['hi', 'is', 'us'] *** Filter list using filter() and a Lambda Function *** Filtered List : ['hi', 'is', 'us'] *** Filter characters from a string using filter() *** Filtered Characters : Hi thi i mple tring, very mple tring *** Filter an array in Python using filter() *** Filtered Array : [1, 4, 21, 33, 45, 77, 88, 99, 32, 55, 77, 22, 4] How do you filter text in a list in Python?Python has a built-in function called filter() that allows you to filter a list (or a tuple) in a more beautiful way. The filter() function iterates over the elements of the list and applies the fn() function to each element. It returns an iterator for the elements where the fn() returns True .
Can you use filter on a string?You can't use filter() on a string as it is an Array.
How do you filter strings?In Java 8 and above, use chars() or codePoints() method of String class to get an IntStream of char values from the given sequence. Then call the filter() method of Stream for restricting the char values to match the given predicate.
How do you filter a specific character in Python?Using 'str.
replace() , we can replace a specific character. If we want to remove that specific character, replace that character with an empty string. The str. replace() method will replace all occurrences of the specific character mentioned.
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