Splitting strings in Python without split()

You can use regular expressions if you want:

>>> import re
>>> s = 'This is a Sentence'
>>> re.findall(r'\S+', s)
['This', 'is', 'a', 'Sentence']

The \S represents any character that isn't whitespace, and the + says to find one or more of those characters in a row. re.findall will create a list of all strings that match that pattern.

But, really, s.split() is the best way to do it.

A recursive version, breaking out the steps in detail:

def my_split(s, sep=' '):
    s = s.lstrip(sep)
    if sep in s:
        pos = s.index(sep)
        found = s[:pos]
        remainder = my_split(s[pos+1:])
        remainder.insert(0, found)
        return remainder
    else:
        return [s]

print my_split("This is a sentence")

Or, the short, one-line form:

def my_split(s, sep=' '):
    return [s[:s.index(sep)]] + my_split(s[s.index(sep)+1:]) if sep in s else [s]

Starting with a list of strings, if you would like to split these strings there are a couple ways to do so depending on what your desired output is.

Case 1: One list of strings (old_list) split into one new list of strings (new_list).

For example ['This is a Sentence', 'Also a sentence'] -> ['This', 'is', 'a', 'Sentence', 'Also', 'a', 'sentence'].

Steps:

1. Loop through the strings. for sentence in old_list:
2. Create a new string to keep track of the current word (word).
3. Loop through the characters in each of these strings. for ch in sentence:
4. If you come across the character(s) you want to split on (spaces in this example), check that word is not empty and add it to the new list, otherwise add the character to word.
5. Make sure to add word to the list after looping through all the characters.

The final code:

new_list = []
for sentence in old_list:
    word = ''
    for ch in sentence:
        if ch == ' ' and word != '':
            new_list.append(word)
            word = ''
        else:
            word += ch
    if word != '':
        new_list.append(word)

This is equivalent to

new_list = []
for sentence in old_list:
    new_list.extend(sentence.split(' '))

or even simpler

new_list =  ' '.join(old_list).split(' ')

Case 2: One list of strings (old_list) split into a new list of lists of strings (new_list).

For example ['This is a Sentence', 'Also a sentence'] -> [['This', 'is', 'a', 'Sentence'], ['Also', 'a', 'sentence']].

Steps:

1. Loop through the strings. for sentence in old_list:
2. Create a new string to keep track of the current word (word) and a new list to keep track of the words in this string (sentence_list).
3. Loop through the characters in each of these strings. for ch in sentence:
4. If you come across the character(s) you want to split on (spaces in this example), check that word is not empty and add it to sentence_list, otherwise add the character to word.
5. Make sure to add word to sentence_list after looping through all the characters.
6. Append (not extend) sentence_list to the new list and move onto the next string.

The final code:

new_list = []
for sentence in old_list:
    sentence_list = []
    word = ''
    for ch in sentence:
        if ch == ' ' and word != '':
            sentence_list.append(word)
            word = ''
        else:
            word += ch
    if word != '':
        sentence_list.append(word)
    new_list.append(sentence_list)

This is equivalent to

new_list = []
for sentence in old_list:
    new_list.append(sentence.split(' '))

or using list comprehensions

new_list =  [sentence.split(' ') for sentence in old_list]

This is simple code to split a char value from a string value; i.e

INPUT : UDDDUDUDU

s = [str(i) for i in input().strip()]
print(s)

OUTPUT: ['U','D','D','D','U','D','U','D','U']

sentence = 'This is a sentence'
word=""
for w in sentence :
    if w.isalpha():
        word=word+w

    elif not w.isalpha():
      print(word)
      word=""
print(word)

string1 = 'bella ciao amigos'
split_list = []
tmp = ''
for s in string1:
   if s == ' ':
       split_list.append(tmp)
       tmp = ''
   else:
       tmp += s
if tmp:
   split_list.append(tmp)

print(split_list)

Output: ------> ['bella', 'ciao', 'amigos']

reverse_list = split_list[::-1]
print(reverse_list)

Output: ------> ['amigos', 'ciao', 'bella']

def mysplit(strng):
    strng = strng.lstrip() 
    strng = strng.rstrip()
    lst=[]
    temp=''
    for i in strng:
        if i == ' ':
            lst.append(temp)
            temp = ''
        else:
            temp += i
    if temp:
        lst.append(temp)
    return lst
     
print(mysplit("Hello World"))
print(mysplit("   "))
print(mysplit(" abc "))
print(mysplit(""))

This is one of the most accurate replicas of split method:

def splitter(x, y = ' '):
    l = []
    for i in range(x.count(y) + 1):
        a = ''
        for i in x:
            if i == y: break
            a += i
        x = x[len(a) + 1 : len(x)]
        l.append(a)
    return ([i for i in l if i != ''])

my_str='This is a sentence'
split_value = []
tmp = ''
for i in my_str+' ':
    if i == ' ':
        split_value.append(tmp)
        tmp = ''
    else:
        tmp += i   
print(split_value)

Just a small modification to the code already given