Category: Programming

This tutorial will show you how to convert an

• octal escape sequence to a Python string, and a
• Python string to an octal escape sequence.

But let’s quickly recap what an octal escape sequence is in the first place!

What Is An Octal Escape Sequence?

An Octal Escape Sequence is a backslash followed by 1-3 octal digits (0-7) such as \150 which encodes the ASCII character 'h'. Each octal escape sequence encodes one character (except invalid octal sequence \000). You can chain together multiple octal escape sequences to obtain a word.

Problem Formulation

Question: How to convert an octal escape sequence to a string and vice versa in Python?

Examples

Python Octal to String Built-In Conversion

You don’t need to “convert” an octal escape sequence to a Unicode string if you already have it represented by a bytes object. Python automatically resolves the encoding.

See here:

>>> b'\101\102\103'
b'ABC'
>>> b'101\040\102\040\103'
b'101 B C'
>>> b'\101\040\102\040\103'
b'A B C'
>>> b'\141\142\143'
b'abc'
>>> b'\150\145\154\154\157'
b'hello'
>>> b'\150\145\154\154\157\040\167\157\162\154\144'
b'hello world'

Python Octal to String Explicit Conversion

The bytes.decode('unicode-escape') function converts a given bytes object represented by an (octal) escape sequence to a Python string. For example, br'\101'.decode('unicode-escape') yields the Unicode (string) character 'A'.

def octal_to_string(x): ''' Converts an octal escape sequence to a string''' return x.decode('unicode-escape')

Example: Convert the octal representations presented above:

octals = [br'\101\102\103', br'\101\040\102\040\103', br'\141\142\143', br'\150\145\154\154\157', br'\150\145\154\154\157\040\167\157\162\154\144'] for octal in octals: print(octal_to_string(octal)) 

This leads to the following expected output:

ABC
A B C
abc
hello
hello world

Python String to Octal

To convert a Python string to an octal escape sequence representation, iterate over each character c and convert it to an octal escape sequence using oct(ord(c)).

The result uses octal representation such as '0o123'. You can do string manipulation, such as slicing and string concatenation, to bring it into the final version '\123', for instance.

Here’s the function that converts string to octal escape sequence format:

def string_to_octal(x): ''' Converts a string to an octal escape sequence''' return '\\' + '\\'.join(oct(ord(c))[2:] for c in x)

Background:

• The ord() function takes a character (=string of length one) as an input and returns the Unicode number of this character. For example, ord('a') returns the Unicode number 97. The inverse function of ord() is the chr() function, so chr(ord('a')) returns the original character 'a'.
• The oct() function takes one integer argument and returns an octal string with prefix "0o".

Let’s check how our strings can be converted to the octal escape sequence representation using this function:

strings = ['ABC', 'A B C', 'abc', 'hello', 'hello world'] for s in strings: print(string_to_octal(s))

And here’s the expected output:

\101\102\103
\101\40\102\40\103
\141\142\143
\150\145\154\154\157
\150\145\154\154\157\40\167\157\162\154\144

If you don’t like the one-liner solution provided above, feel free to use this multi-liner instead that may be easier to read:

def string_to_octal(x): ''' Converts a string to an octal escape sequence''' result = '' for c in x: result += '\\' + oct(ord(c))[2:] return result

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Summary: The most efficient way to split a string using variable spaces is to use the split function like so given_string.split(). An alternate approach is to use different functions of the regex package to split the string at multiple whitespaces.

Minimal Example

text = "a b c d"
# Method 1
print(text.split())
# Method 2
import re
print(re.split('\s+', text))
# Method 3
print([x for x in re.findall(r'\S+', text) if x != ''])
# Method 4
print(re.sub(r'\s+', ',', text).split(','))
# Method 5
print(list(filter(None, text.split()))) # ['a', 'b', 'c', 'd']

Problem Formulation

Problem: Given a string. How will you split the string using multiple spaces?

Example

# Input
text = "abc xyz lmn pqr"
# Output
['abc', 'xyz', 'lmn', 'pqr']

The given input has multiple spaces between each substring, i.e., there are three spaces after abc, two spaces after xyz while a single space after lmn. So, not only do you have multiple spaces between the substring but also varied number of spaces. Can you split the string by varied and multiple spaces?

Though the question might look daunting at first but once you get hold of it, the solutions to this problem are easier than one can imagine. So, without further delay let us dive into the different ways of solving the given problem.

Method 1: Using split()

The built-in split('sep') function allows you to split a string in Python based on a given delimiter. By default the split function splits a given string at whitespaces. Meaning, if you do not pass any delimiter to the split function then the string will be split at whitespaces.

You can use this default property of the split function and successfully split the given string at multiple spaces just by using the split() function.

Code:

text = "abc xyz lmn pqr"
print(text.split()) # ['abc', 'xyz', 'lmn', 'pqr']

Recommended Digest: Python String split()

Method 2: Using re.split

The re.split(pattern, string) method matches all occurrences of the pattern in the string and divides the string along the matches resulting in a list of strings between the matches. For example, re.split('a', 'bbabbbab') results in the list of strings ['bb', 'bbb', 'b'].

Approach: To split the string using multiple space characters use re.split("\s+", text) where \s+ is the matching pattern and it represents a special sequence that returns a match whenever it finds any whitespace character and splits the string. So, whenever there’s a space or multiple spaces (any number of occurrences of space are whitespace characters) the string will be split.

Code:

import re
text = "abc xyz lmn pqr"
print(re.split('\s+', text))
# ['abc', 'xyz', 'lmn', 'pqr']

Recommended Read:  Python Regex Split.

Method 3: Using re.findall

The re.findall(pattern, string) method scans the string from left to right, searching for all non-overlapping matches of the pattern. It returns a list of strings in the matching order when scanning the string from left to right.

Recommended Read: Python re.findall() – Everything You Need to Know

Code:

import re
text = "abc xyz lmn pqr"
print([x for x in re.findall(r'\S+', text) if x != ''])
# ['abc', 'xyz', 'lmn', 'pqr']

Method 4: Using re.sub

The regex function re.sub(P, R, S) replaces all occurrences of the pattern P with the replacement R in string S. It returns a new string. For example, if you call re.sub('a', 'b', 'aabb'), the result will be the new string 'bbbb' with all characters 'a' replaced by 'b'.

Approach: Use the re.sub method to replace all occurrences of space characters in the given string with a comma. Thus, the string will now have commas instead of space characters and you can simply split it using a normal string split method by passing comma as the delimiter.

Silly! Isn’t it? Nevertheless, it works.

Code:

import re
text = "abc xyz lmn pqr"
res = re.sub(r'\s+', ',', text).split(',')
print(res)
# ['abc', 'xyz', 'lmn', 'pqr']

Method 5: Using filter

Python’s built-in filter() function filters out the elements that pass a filtering condition. It takes two arguments: function and iterable. The function assigns a Boolean value to each element in the iterable to check whether the element will pass the filter or not. It returns an iterator with the elements that pass the filtering condition.

Related Read: Python filter()

Approach: You can use the filter() method to split the string by space. Feed in None as the first argument and the list of split strings as the second argument into the filter function. The filter() function then iterates through the list and filters out the spaces from the given string and returns only the non-whitespace characters. As the filter() method returns an object, we need to use the list() to convert the object into a list.

Code:

text = "abc xyz lmn pqr"
print(list(filter(None, text.split())))
# ['abc', 'xyz', 'lmn', 'pqr']

Conclusion

Hurrah! We have successfully solved the given problem using as many as five different ways. I hope you enjoyed reading this article and it helped you in your Python coding journey. Please subscribe and stay tuned for more interesting articles!

Happy coding!

Suggested Read: Python Regex Superpower [Full Tutorial]

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Summary: The most efficient way to split a string using multiple whitespaces is to use the split function like so given_string.split(). An alternate approach is to use different functions of the regex package to split the string at multiple whitespaces.

Minimal Example:

import re text = "mouse\nsnake\teagle human"
# Method 1
print(text.split()) # Method 2
res = re.split("\s+", text)
print(res) # Method 3
res = re.sub(r'\s+', ',', text).split(',')
print(res) # Method 4
print(re.findall(r'\S+', text)) # ['mouse', 'snake', 'eagle', 'human']

Problem Formulation

Problem: Given a string. How will you split the string using multiple whitespaces?

Example

# Input
text = "abc\nlmn\tpqr xyz\rmno"
# Output
['abc', 'lmn', 'pqr', 'xyz', 'mno']

There are numerous ways of solving the given problem. So, without further ado, let us dive into the solutions.

Method 1: Using Regex

The best way to deal with multiple delimiters is to use the flexibility of the regular expressions library. There are different functions available in the regex library that you can use to split the given string. Let’s go through each one by one.

1.1 Using re.split

The re.split(pattern, string) method matches all occurrences of the pattern in the string and divides the string along the matches resulting in a list of strings between the matches. For example, re.split('a', 'bbabbbab') results in the list of strings ['bb', 'bbb', 'b'].

Recommended Read:  Python Regex Split.

Approach: To split the string using multiple whitespace characters use re.split("\s+", text) where \s is the matching pattern and it represents a special sequence that returns a match whenever it finds any whitespace character and splits the string.

Code:

import re
text = "abc\nlmn\tpqr xyz\rmno"
res = re.split("\s+", text)
print(res) # ['abc', 'lmn', 'pqr', 'xyz', 'mno']

1.2 Using re.findall

The re.findall(pattern, string) method scans the string from left to right, searching for all non-overlapping matches of the pattern. It returns a list of strings in the matching order when scanning the string from left to right.

Recommended Read: Python re.findall() – Everything You Need to Know

Code:

import re text = "abc\nlmn\tpqr xyz\rmno"
print(re.findall(r'\S+', text))

Explanation: In the expression, i.e., re.findall(r"\S'+", text), all occurrences of characters except whitespaces are found and stored in a list. Here, \S+ returns a match whenever the string contains one or more occurrences of normal characters (characters from a to Z, digits from 0-9, etc. However, not the whitespaces are considered).

1.3 Using re.sub

The regex function re.sub(P, R, S) replaces all occurrences of the pattern P with the replacement R in string S. It returns a new string. For example, if you call re.sub('a', 'b', 'aabb'), the result will be the new string 'bbbb' with all characters 'a' replaced by 'b'.

Aprroach: Use the re.sub method to replace all occurrences of whitespace characters in the given string with a comma. Thus, the string will now have commas instead of whitespace characters and you can simply split it using a normal string split method by passing comma as the delimiter.

Code:

import re
text = "abc\nlmn\tpqr xyz\rmno"
res = re.sub(r'\s+', ',', text).split(',')
print(res) # ['abc', 'lmn', 'pqr', 'xyz', 'mno']

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Method 2: Using split()

By default the split function splits a given string at whitespaces. Meaning, if you do not pass any delimiter to the split function then the string will be split at whitespaces. You can use this default property of the split function and successfully split the given string at multiple whitespaces just by using the split() function.

Code:

text = "abc\nlmn\tpqr xyz\rmno"
print(text.split())
# ['abc', 'lmn', 'pqr', 'xyz', 'mno']

Recommended Digest: Python String split()

Conclusion

We have successfully solved the given problem using different approaches. Simply using split could do the job for you. However, feel free to explore and try out the other options mentioned above. I hope this article helped you in your Python coding journey. Please subscribe and stay tuned for more interesting articles.

Happy Pythoning!  

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Summary: To split a string by a number, use the regex split method using the “\d” pattern.

Minimal Example

my_string = "#@1abc3$!*5xyz" # Method 1
import re res = re.split('\d+', my_string)
print(res) # Method 2
import re res = re.findall('\D+', my_string)
print(res) # Method 3
from itertools import groupby li = [''.join(g) for _, g in groupby(my_string, str.isdigit)]
res = [x for x in li if x.isdigit() == False]
print(res) # Method 4
res = []
for i in my_string: if i.isdigit() == True: my_string = my_string.replace(i, ",")
print(my_string.split(",")) # Outputs:
# ['#@', 'abc', '$!*', 'xyz']

Problem Formulation

Problem: Given a string containing different characters. How will you split the string whenever a number appears?

Method 1: re.split()

The re.split(pattern, string) method matches all occurrences of the pattern in the string and divides the string along the matches resulting in a list of strings between the matches. For example, re.split('a', 'bbabbbab') results in the list of strings ['bb', 'bbb', 'b'].

Code:

import re
my_string = "#@1abc3$!*5xyz"
res = re.split('\d+', my_string)
print(res) # ['#@', 'abc', '$!*', 'xyz']

Explanation: The \d special character matches any digit between 0 and 9. By using the maximal number of digits as a delimiter, you split along the digit-word boundary. 

Method 2: re.findall()

The re.findall(pattern, string) method scans string from left to right, searching for all non-overlapping matches of the pattern. It returns a list of strings in the matching order when scanning the string from left to right.

Code:

import re
my_string = "#@1abc3$!*5xyz"
res = re.findall('\D+', my_string)
print(res) # ['#@', 'abc', '$!*', 'xyz']

Explanation: The \D special character matches all characters except any digit between 0 and 9. Thus, you are essentially finding all character groups that appear before the occurrence of a digit.

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Method 3: itertools.groupby()

Code:

from itertools import groupby
my_string = "#@1abc3$!*5xyz"
li = [''.join(g) for _, g in groupby(my_string, str.isdigit)]
res = [x for x in li if x.isdigit() == False]
print(res) # ['#@', 'abc', '$!*', 'xyz']

Explanation:

• The itertools.groupby(iterable, key=None) function creates an iterator that returns tuples (key, group-iterator) grouped by each value of key. We use the str.isdigit() function as key function.
• The str.isdigit() function returns True if the string consists only of numeric characters. Thus, you will have a list created by using numbers as separators. Note that this list will also contain the numbers as items within it.
• In order to eliminate the numbers, use another list comprehension that checks if an element in the list returned previously is a digit or not with the help of the isdigit method. If it is a digit, the item will be discarded. Otherwise it will be stored in the list.

Method 4: Replace Using a for Loop

Approach: Use a for loop to iterate through the characters of the given string. Check if a character is a digit or not. As soon as a digit is found, replace that character/digit with a delimiter string ( we have used a comma here) with the help of the replace() method. This basically means that you are placing a particular character in the string whenever a number appears. Once all the digits are replaced by the separator string, split the string by passing the separator string as a delimiter to the split method.

Code:

my_string = "#@1abc3$!*5xyz"
res = []
for i in my_string: if i.isdigit(): my_string = my_string.replace(i, ",")
print(my_string.split(",")) # ['#@', 'abc', '$!*', 'xyz']

Conclusion

Phew! We have successfully solved the given problem and managed to do so using four different ways. I hope you found this article helpful and it answered your queries. Please subscribe and stay tuned for more solutions and tutorials.

Happy coding!

Related Read: How to Split a String Between Numbers and Letters?

Problem Formulation

Given a string in the octal form:

s = '0o77'
# or s = '77'

How to convert the octal string to an integer in Python?

For example, you want to convert the octal string 'o10' to the decimal integer 8.

Here are a few other examples:

Oct String to Integer using int() with Base 8

To convert an octal string to an integer, pass the string as a first argument into Python’s built-in int() function. Use base=8 as a second argument of the int() function to specify that the given string is an octal number. The int() function will then convert the octal string to an integer with base 10 and return the result.

Here’s a minimal example:

>>> int('0o77', base=8)
63

Examples

And here’s how you can convert the additional examples shown above:

>>> int('0o0', base=8)
0
>>> int('0o4', base=8)
4
>>> int('0o10', base=8)
8
>>> int('0o14', base=8)
12
>>> int('0o20', base=8)
16
>>> int('0o77', base=8)
63
>>> int('0o77777', base=8)
32767

You actually don’t need to use the prefix '0o' because your second argument already defines unambiguously that the given string is an octal number:

>>> int('0', base=8)
0
>>> int('4', base=8)
4
>>> int('10', base=8)
8
>>> int('14', base=8)
12
>>> int('20', base=8)
16
>>> int('77', base=8)
63
>>> int('77777', base=8)
32767

However, skipping the base but leaving the prefix raises a ValueError: invalid literal for int() with base 10: '0o77':

>>> int('0o77')
Traceback (most recent call last): File "<pyshell#16>", line 1, in <module> int('0o77')
ValueError: invalid literal for int() with base 10: '0o77'

It assumes that the input string is in base 10 when in fact, it isn’t.

Note: Even though passing a prefixed string '0o...' into the int() function is unambiguous, Python’s int() function doesn’t accept it if you don’t also define the base. This may be fixed in future versions!

In fact, you can specify the base argument as 0 to switch on base guessing—which should be the default behavior anyway!

Base Guessing

You can pass a prefixed string '0o...' into the int() function and set the base to 0 to switch on base guessing in Python. This uses the prefix to determine the base automatically—without you needing to set it to 16. Yet, you still have to set it to 0 so the benefit is marginal in practice.

>>> int('0o7', base=8)
7
>>> int('0o7', base=0)
7
>>> int('0o7', 0)
7

Converting Octal Literals to Int

If you don’t have an octal string but a octal number—called a literal—such as 0xff, you don’t even need the int() function because Python will automatically convert it to a decimal number:

>>> 0o743
483
>>> 0o7
7
>>> 0o10
8

Background int()

Syntax: int(value [, base]) – > int

Do you still need more background information about Python’s built-in int() function? No problem, read over the related tutorial.

Related Tutorial: Python’s Built-in int() Function

Summary: Use "given string".split('-') to split the given string by hyphen and store each word as an individual item in a list. Some other ways to split using hyphen include using a list comprehension and the regex library.

Minimal Example

text = "Violet-Indigo-Blue-Green-Yellow-Orange-Red"
# Method 1
print(text.split("-"))
# Method 2
import re
print(re.split('-', text))
# Method 3
print(list(filter(None, text.split('-'))))
# Method 4
print([x for x in re.findall(r'[^-]*|(?!-).*$', text) if x != '']) # OUTPUT: ['Violet', 'Indigo', 'Blue', 'Green', 'Yellow', 'Orange', 'Red']

Problem Formulation

Problem: Given a string, how will you split the string into a list of words using the hyphen as a delimiter?

Example

Let’s understand the problem with the help of an example.

# Input:
text = "Violet-Indigo-Blue-Green-Yellow-Orange-Red"
# Output:
['Violet', 'Indigo', 'Blue', 'Green', 'Yellow', 'Orange', 'Red']

Now without any further ado, let’s dive into the numerous ways of solving this problem.

Method 1: Using split()

Python’s built-in split() function splits the string at a given separator and returns a split list of substrings. Here’s how the split() function works: 'finxterx42'.split('x') will split the string with the character ‘x’ as the delimiter and return the following list as an output: ['fin', 'ter', '42'].

Approach: To split a string by hyphen, you can simply pass the underscore as a separator to the split('-') function.

Code:

text = "Violet-Indigo-Blue-Green-Yellow-Orange-Red"
print(text.split("-")) # ['Violet', 'Indigo', 'Blue', 'Green', 'Yellow', 'Orange', 'Red']

Related Read: Python String split()

Method 2: Using re.split()

Another way of separating a string by using the underscore as a separator is to use the re.split() method from the regex library. The re.split(pattern, string) method matches all occurrences of the pattern in the string and divides the string along the matches resulting in a list of strings between the matches. For example, re.split('a', 'bbabbbab') results in the list of strings ['bb', 'bbb', 'b'].

Approach: You can use the re.split() method as re.split('-', text) where '-' returns a match whenever the string contains a hyphen. Whenever any hyphen is encountered, the text gets separated and the split substring gets stored as an element within the resultant list.

Code:

import re
text = "Violet-Indigo-Blue-Green-Yellow-Orange-Red"
print(re.split('-', text)) # ['Violet', 'Indigo', 'Blue', 'Green', 'Yellow', 'Orange', 'Red']

Related Read: Python Regex Split

Method 3: Using filter()

Note: This approach is efficient when the resultant list contains empty strings along with substrings.

Python’s built-in filter() function filters out the elements that pass a filtering condition. It takes two arguments: function and iterable. The function assigns a Boolean value to each element in the iterable to check whether the element will pass the filter or not. It returns an iterator with the elements that passes the filtering condition.

Approach: Use the filter() method to split the string by hyphen. The function takes None as the first argument and the list of split strings as the second argument. The filter() function then iterates through the list and removes any empty elements. As the filter() method returns an object, we need to use the list() to convert the object into a list.

Code:

text = "Violet-Indigo-Blue-Green-Yellow-Orange-Red" print(list(filter(None, text.split('-')))) # ['Violet', 'Indigo', 'Blue', 'Green', 'Yellow', 'Orange', 'Red']

Related Read: Python filter()

Method 4: Using re.findall()

The re.findall(pattern, string) method scans the string from left to right, searching for all non-overlapping matches of the pattern. It returns a list of strings in the matching order- when scanning the string from left to right.

Approach: You can use the re.findall() method from the regex module to split the string by hyphen. Use ‘[^-]|(?!-).$‘ as the pattern that can be fed into the findall function to solve the problem. It simply, means a set all characters that are joined by a hyphen will be grouped together.

Code:

import re
text = "Violet-Indigo-Blue-Green-Yellow-Orange-Red" print([x for x in re.findall(r'[^_]*', text) if x != '']) # ['Python', 'Pycharm', 'Java', 'Eclipse', 'Golang', 'VisualStudio']

Related Read: Python re.findall() – Everything You Need to Know

Python | Split String by Dot

Now that we have gone through numerous ways of solving the given problem, here’s a similar programming challenge for you to solve.

Challenge: You are given a string that contains dots in it. How will you split the string using a dot as a delimiter? Consider the code below and try to split the string by dot.

# Input:
text = "stars.moon.sun.sky" # Expected Output:
['stars', 'moon', 'sun', 'sky']

Try to solve the problem yourself before looking into the given solutions.

Solution: Here are the different methods to split a string by using the dot as a delimiter/separator:

text = "a*b*c"
# Method 1
print(text.split("*")) # Method 2
print(list(filter(None, text.split('*')))) # Method 3
import re
print([x for x in re.findall(r'[^/*]*|(?!/*).*$', text) if x != '']) # Method 4
print(re.split('[/*]', text))

Conclusion

Hurrah! We have successfully solved the given problem using as many as four different ways. We then went on to solve a similar coding challenge. I hope this article helped you. Please subscribe and stay tuned for more interesting articles!

Happy coding!

Do you want to master the regex superpower? Check out my new book The Smartest Way to Learn Regular Expressions in Python with the innovative 3-step approach for active learning: (1) study a book chapter, (2) solve a code puzzle, and (3) watch an educational chapter video.

Summary: Use "given string".split() to split the given string by underscore and store each word as an individual item in a list.

Minimal Example

text = "Welcome_to_the_world_of_Python"
# Method 1
print(text.split("_")) # Method 2
import re
print(re.split('_', text)) # Method 3
print(list(filter(None, text.split('_')))) # Method 4
print([x for x in re.findall(r'[^_]*|(?!_).*$', text) if x != '']) # OUTPUT: ['Welcome', 'to', 'the', 'world', 'of', 'Python']

Problem Formulation

Problem: Given a string, how will you split the string into a list of words using the underscore as a delimiter?

Example

Let’s understand the problem with the help of an example.

# Input:
text = "Python_Pycharm_Java_Eclipse_Golang_VisualStudio"
# Output:
['Python', 'Pycharm', 'Java', 'Eclipse', 'Golang', 'VisualStudio']

Now without any further ado, let’s dive into the numerous ways of solving this problem.

Method 1: Using split()

Python’s built-in split() function splits the string at a given separator and returns a split list of substrings. Here’s how the split() function works: 'finxterx42'.split('x') will split the string with the character ‘x’ as the delimiter and return the following list as an output: ['fin', 'ter', '42'].

Approach: To split a string by underscore, you need to use the underscore as the delimiter. You can simply pass the underscore as a separator to the split('_') function.

Code:

text = "Python_Pycharm_Java_Eclipse_Golang_VisualStudio"
print(text.split("_")) # ['Python', 'Pycharm', 'Java', 'Eclipse', 'Golang', 'VisualStudio']

Related Read: Python String split()

Method 2: Using re.split()

Another way of separating a string by using the underscore as a separator is to use the re.split() method from the regex library. The re.split(pattern, string) method matches all occurrences of the pattern in the string and divides the string along the matches resulting in a list of strings between the matches. For example, re.split('a', 'bbabbbab') results in the list of strings ['bb', 'bbb', 'b'].

Approach: You can simply use the re.split() method as re.split('_', text) where '_' returns a match whenever the string contains an underscore. Whenever any underscore is encountered, the text gets separated at that point.

Code:

import re
text = "Python_Pycharm_Java_Eclipse_Golang_VisualStudio"
print(re.split('_', text)) # ['Python', 'Pycharm', 'Java', 'Eclipse', 'Golang', 'VisualStudio']

Related Read: Python Regex Split

Method 3: Using filter()

Python’s built-in filter() function filters out the elements that pass a filtering condition. It takes two arguments: function and iterable. The function assigns a Boolean value to each element in the iterable to check whether the element will pass the filter or not. It returns an iterator with the elements that passes the filtering condition.

Approach: You can use the filter() method to split the string by underscore. The function takes None as the first argument and the list of split strings as the second argument. The filter() function iterates through the list and removes any empty elements. As the filter() method returns an object, we need to use the list() to convert the object into a list.

Code:

text = "Python_Pycharm_Java_Eclipse_Golang_VisualStudio"
print(list(filter(None, text.split('_')))) # ['Python', 'Pycharm', 'Java', 'Eclipse', 'Golang', 'VisualStudio']

Related Read: Python filter()

Method 4: Using re.findall()

The re.findall(pattern, string) method scans the string from left to right, searching for all non-overlapping matches of the pattern. It returns a list of strings in the matching order- when scanning the string from left to right.

Approach: You can use the re.findall() method from the regex module to split the string by underscore. You can use ‘[^_]‘ as the pattern that can be fed into the findall function to solve the problem. It simply, means a set all characters that start with an underscore will be grouped together.

Code:

import re
text = "Python_Pycharm_Java_Eclipse_Golang_VisualStudio"
print([x for x in re.findall(r'[^_]*', text) if x != '']) # ['Python', 'Pycharm', 'Java', 'Eclipse', 'Golang', 'VisualStudio']

Related Read: Python re.findall() – Everything You Need to Know

Python | Split String by Dot

Now that we have gone through numerous ways of solving the given problem, here’s a similar programming challenge for you to solve.

Challenge: You are given a string that contains dots in it. How will you split the string using a dot as a delimiter? Consider the code below and try to split the string by dot.

# Input:
text = "stars.moon.sun.sky" # Expected Output:
['stars', 'moon', 'sun', 'sky']

Try to solve the problem yourself before looking into the given solutions.

Solution: Here are the different methods to split a string by using the dot as a delimiter/separator:

text = "stars.moon.sun.sky"
# Method 1
print(text.split(".")) # Method 2
print(list(filter(None, text.split('.')))) # Method 3
import re
print([x for x in re.findall(r'[^.]*|(?!.).*$', text) if x != '']) # Method 4
print(re.split('\\.', text))

Conclusion

Hurrah! We have successfully solved the given problem using as many as four different ways. I hope you enjoyed this article and it helps you in your Python coding journey. Please subscribe and stay tuned for more interesting articles!

Do you want to master the regex superpower? Check out my new book The Smartest Way to Learn Regular Expressions in Python with the innovative 3-step approach for active learning: (1) study a book chapter, (2) solve a code puzzle, and (3) watch an educational chapter video.