⭐Summary: To get the first “N” characters of a string slice, the string from the starting index until the Nth character using Python’s slice notation.
text = "akjvdkavkjsdvkja" # Get first 3 characters print(text[:3]) # OUTPUT: akj
📜Problem: Given a string. How will you get the first “N” characters of the string?
In the following example, you just have to extract the first 5 characters from the given string.
# INPUT text = 'abcdefghijklmnopqr' n = 5 # OUTPUT abcde
In the following example, you first have to split the string and get the words/substrings out of it and then extract the first three characters from each substring.
# Input text = "eagdef-ernopqr-essvwxyz" # Output eagerness
Solution: Split and Slice the String
Approach to Solve Example 1: Slice the string using square bracket notation and extract the required number of characters using their indices.
Since we need the first 5 characters, you can simply slice the string starting from 0 until 5. This means the start value is 0 while the stop value is 5.
text = 'abcdefghijklmnopqr' n = 5 print(text[0:n]) # abcde
Approach to Solve Example 2: You have to go a step further to solve the second scenario. Here, you have to first split the string using the given delimiter (“-“) which will create a list of substrings. Now in order to extract the first three characters from each substring simply iterate through each item of the list using a for loop and slice out the first three characters from each element in each iteration with the help of slice notation.
text = "eagdef-ernopqr-essvwxyz" res = text.split('-') for i in res: print(i[:3], end='') # eagerness
Slicing is a concept to carve out a substring from a given string. Use slicing notation
s[start:stop:step] to access every
step-th element starting from index
start (included) and ending in index
stop (excluded). All three arguments are optional, so you can skip them to use the default values (
step=1). For example, the expression
s[2:4] from string
'hello' carves out the slice
'll' and the expression
s[:3:2] carves out the slice
Related Read: Introduction to Slicing in Python
🍎Qs 1: How to Split a String After Every N Characters?
Solution: One of the easiest ways to split a string after every n character is to use a list comprehension to and slice the string accordingly to extract every
n character of the given string and store them in a list. The items of this list represent the required split substrings.
given_string = 'abcdef' n = 3 print([(given_string[i:i+n]) for i in range(0, len(given_string), n)]) # OUTPUT: ['abc', 'def']
Read More: Python | Split String Every “N” Characters
🍎Qs 2: How to Split a String and Get the Nth Element?
Solution: Split the string normally at the occurrence of the given delimiter using the
split method. To extract the required element from the list use its index within square brackets.
text = "Welcome to the world of Python!" res = text.split() print("Split substrings: ", res) print("Required Element: ", res) # OUTPUT: # Split substrings: ['Welcome', 'to', 'the', 'world', 'of', 'Python!'] # Required Element: world
Read More: Python | Split String Get Element
🍎Qs 3: How to Split a String and Get First N elements?
Approach: Split the string using the split function and the given delimiter. Then extract the first “N” characters from the split list of substrings using their index.
text = 'abc-efg-xyz-lmn-pqr' res = text.split('-') for i in range(3): print(res[i], end=" ") # abc efg xyz
🍎Qs 4: How to Split a String and Get the Last “N” Elements?
Solution: Split the string using Python’s built-in
split method and the given separator. To extract the last three elements from this split list, iterate in a reverse range starting from -3 until 0. This will allow you to grab the last three elements from the list using their negative indices.
text = 'abc-efg-xyz-lmn-pqr' res = text.split('-') for i in range(-3, 0): print(res[i], end=" ") # xyz lmn pqr
I hope the questions and their solutions discussed in this article have helped you. Please subscribe and stay tuned for more interesting solutions and discussions in the future.
Happy coding! 🙂
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