Check if text within a list is withing a string

Question

I would like to check against a list of words if they are within a string.

For Example:

listofwords = ['hi','bye','yes','no']

String = 'Hi how are you'
string2 = 'I have none of the words'

String 1 is true as it contains 'hi' and string2 is false as it does not.

I have tried the following code but it always returns false.

if any(ext in String for ext in listofwords):
   print(String)

I would also like to show what the matching word was to check this is correct.

do you want to print the entire string or only the matching words? — Umar.H
– Umar.H, Commented Jul 30, 2019 at 13:07
Check updated answer. The key idea is to user .lower function on strings before making comparisons. If you want to print words( here assuming words mean space seperated words) just iterate over and do matching. — Poojan
– Poojan, Commented Jul 30, 2019 at 14:51

Poojan · Accepted Answer · 2019-09-11 18:29:59Z

5

hi and Hi are different words. Use .lower before comparing.

if any(ext.lower() in String.lower() for ext in listofwords):
   print(String)

Update:

to print matching word use for loop to iterate and print words that match.

Example:

listofwords = ['hi','bye','yes','no']

String = 'Hi how are you'
string2 = 'I have none of the words'

for word in listofwords:
    if word.lower() in map(str.lower,String.split()): # map both of the words to lowercase before matching
        print(word)


for word in listofwords:
    if word.lower() in map(str.lower,string2.split()): # map both of the words to lowercase before matching
        print(word)

PS: Not the optimized version. You can store String.split results in a list and then start iterating that will save time for larger strings. But purpose of the code is to demonstrate use of lower case.

edited Sep 11, 2019 at 18:29

answered Jul 30, 2019 at 13:05

Poojan

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2 Comments

Poojan Over a year ago

@AndrejKesely OP stats his problem. Its returning False in every case given the code. I just gave suggestion on mistake. His code do not mention anything about string2

Jarratt Perkins Over a year ago

Would this also allow me to return the actual matched value in the string ->ext.lower()

Carsten · Accepted Answer · 2019-07-30 13:06:16Z

2

Python is case sensitive. Hence hi is not equal to Hi. This works:

listofwords = ['hi','bye','yes','no']

String = 'hi how are you'
string2 = 'I have none of the words'

if any(ext in String for ext in listofwords):
   print(String)

answered Jul 30, 2019 at 13:06

Carsten

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2 Comments

Poojan Over a year ago

There is no need to change string manually. Instead use lower to do same. What will you do when string is very long or entered by user input.

Carsten Over a year ago

Well, depends on your use case I would say

Djaouad · Accepted Answer · 2019-07-30 13:20:46Z

0

The problem is both with case-sensitivity and with using in directly with a string.

If you want to make your search case-insensitive, consider converting both the String and the word to lower case, also, you should split the string after lower casing it, if you want to properly search for words:

if any(ext.lower() in String.lower().split() for ext in listofwords):
   print(String)

Splitting avoids returning True for strings like no in none and only works if no (or any other word) is present on its own. So now the above will work for both String (it will print it) and for string2 (it will not print it).

edited Jul 30, 2019 at 13:20

answered Jul 30, 2019 at 13:07

Djaouad

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2 Comments

Jarratt Perkins Over a year ago

Thanks for taking this 1 step further. Would this also allow me to return the actual matched value in the string ->ext.lower()

Djaouad Over a year ago

@JarrattPerkins You can get the matched value, in fact there could be many values that exist in the list and in the string.

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