Re-arrange numbers in string python

Rearrange Numbers in String

Given a string, write a program to re-arrange all the numbers appearing in the string in decreasing order. Note: There will not be any negative numbers or numbers with decimal part.

Input

The input will be a single line containing a string.

Output

The output should be a single line containing the modified string with all the numbers in string re-ordered in decreasing order.

Explanation:

For example, if the given string is "I am 5 years and 11 months old", the numbers are 5, 11. Your code should print the sentence after re-ordering the numbers as "I am 11 years and 5 months old".

#Sample Input:
I am 5 years and 11 months old

#Sample Output:
I am 11 years and 5 months old

#Sample input:
I am 28 years 9 months 11 weeks and 55 days old

#Sample output:
I am 55 years 28 months 11 weeks and 9 days old

My approach:

def RearrangeNumbers(source):
    tmp0 = list(source)
    tmp1 = [c if c.isdigit() else ' ' for. 
             c in tmp0 ]
    tmp2 = "".join(tmp1)
    tmp3 = tmp2.split()
    numbers = []
    for w in tmp3:
        numbers.append(int(w))
    if len(numbers) < 2:
        return source
    numbers.sort(reverse=True)
    result_string = ''
    i = 0
    while i < len(source): 
        c = source[i]
        if not c.isdigit():
            result_string += c
        else:
            result_string += str(numbers[0])
            numbers = numbers[1:]
            i+=1
        i+=1
    return result_string

print(RearrangeNumbers(input()))

Output:

I am 55 years 28months 11 weeks and 9 days old

But there should be space between 28months

asked Jul 9, 2021 at 11:12

1

You do a lot of string manipulation on a character by character basis in your code. Finding numbers digit-wise is a complicated way to do what you must do. Your lost space is caused by your approach:

Hint: check the length's of your numbers in your text - you may not always replace a 1-digit number by another 1-digit number - sometimes you would need to replace a 1-digit number by a 3 digit number:

"Try 1 or 423 or 849 things."

and in that case your "char-by-char" replacing will get wonky and you loose the space.

Essentially you replace "2 " by a 2-digit number (or "12 " by a 3-digit one etc. killing the space).

It would be better to

• detect all numbers
• sort detected numbers by their integer value descending
• replace all detected numbers in your text with format-placeholder '{}'
• use string.formt() to substitute numbers in correct order

like so:

def sortNumbers(text):
    # replace all non-digit characters by space, split result
    numbers = ''.join(t if t.isdigit() else ' ' for t in text).split()

    # order descending by integer value
    numbers.sort(key=lambda x:-int(x))  

    # replace all found numbers - do not mess with the original string with 
    # respect to splitting, spaces or anything else - multiple spaces
    # might get reduced to 1 space if you "split()" it.
    for n in numbers:
        text = text.replace(n, "{}")

    return text.format(*numbers)  # put the sorted numbers back into the string

for text in ["I am 5 years and 11 months old",
            "I am 28 years 9 months 11 weeks and 55 days old",
            "What is 5 less then 45?",
            "At 49th Street it is 500.", "It is $23 and 45."]:

    print(sortNumbers(text))

Output:

I am 11 years and 5 months old
I am 55 years 28 months 11 weeks and 9 days old
What is 45 less then 5?
At 500th Street it is 49.
It is $45 and 23.

answered Jul 9, 2021 at 11:36

Patrick ArtnerPatrick Artner

49k8 gold badges44 silver badges66 bronze badges

1

You could use a regular expression to find all numbers:

import re
inp = 'I am 28 years 9 months 11 weeks and 55 days old'
numbers = tuple(sorted(map(int, re.findall(r'([\d]+)', inp)), reverse=True)) # find all numbers, converts each number to int, sort them and convert to tuple
inpPlaceholders = re.sub(r'([\d]+)', '%s', inp) # replace all numbers in the string to %s placeholders
print(inpPlaceholders % numbers) # rebuild the string, using %s string formatting

Out:

I am 55 years 28 months 11 weeks and 9 days old

answered Jul 9, 2021 at 11:36

Maurice MeyerMaurice Meyer

15.7k3 gold badges23 silver badges44 bronze badges

You can try this:

def RearrangeNumbers(source):
    tmp0=source.split()
    int_l=[]
    for j,i in enumerate(tmp0):
      try:
        tmp0[j]=int(i)
        int_l.append(int(i))
      except ValueError:
        pass
    int_l.sort()
    for j,i in enumerate(tmp0):
      if isinstance(i,int):
        tmp0[j]=str(int_l[0])
        int_l.pop(0)
    return ' '.join(tmp0)

print(RearrangeNumbers(input()))

Sample run.

I am 28 years 9 months 11 weeks and 55 days old
I am 9 years 11 months 28 weeks and 55 days old

answered Jul 9, 2021 at 11:39

You can use string.split() and list comprehension. To populate the new string you can transform the sorted list of numbers in an iterator:

string = "I am 28 years 9 months 11 weeks and 55 days old"

numbers = [int(substring) for substring in string.split() if substring.isdigit()]
sorted_numbers = iter(sorted(numbers, reverse=True))
output =  " ".join([substring if not substring.isdigit() else str(next(sorted_numbers)) for substring in string.split()])

print(output)

# I am 55 years 28 months 11 weeks and 9 days old

answered Jul 9, 2021 at 12:15

frabfrab

1,0981 gold badge3 silver badges13 bronze badges

You can use re.sub and re.findall:

import re
def reposition(s):
   return re.sub('\d+', '{}', s).format(*sorted(map(int, re.findall('\d+', s)), reverse=True))

vals = ['I am 5 years and 11 months old', 'I am 28 years 9 months 11 weeks and 55 days old']
result = [reposition(i) for i in vals]

Output:

['I am 11 years and 5 months old', 'I am 55 years 28 months 11 weeks and 9 days old']

answered Jul 9, 2021 at 16:00

Ajax1234Ajax1234

67.3k7 gold badges58 silver badges98 bronze badges

this code is lengthy and only for beginner those who just started coding and stuck at some point and unable to solve the problem but need to complete it.

string_list = input().split(" ")
num_list = []
new_list = []
for each_word in string_list:
    num = ''
    new_word = ''
    for each_char in enumerate(each_word):
        index, character = each_char
        if (character.isdigit()) :
            num += character
        elif(character.isdigit() == False and num != ''): 
            num_list += [int(num)]
            num = ''
            new_word += "{}" + character 
        else:
            new_word += character

    if (each_word.isdigit() or num != ''):
        num_list += [int(num)]
        new_word += "{}"
    if new_word != '':
        new_list += [new_word]
    if each_word == "":
        new_list += [""]


num_list = sorted(num_list, reverse= True)
print(" ".join(new_list).format(*num_list))

answered May 30 at 20:06

How do I rearrange strings in CPP?

How do you rearrange words in Python?

How do you convert a list to a string in Python?

How do you rearrange numbers in a string in python?