How do you reverse a positive and negative integer in python?

Questions : python-How to reverse an negative integer or non-integer

2022-10-06T10:36:56+00:00 2022-10-06T10:36:56+00:00

857

I am learning python and I meet some anycodings_python troubles.

I want to write the script to reverse a anycodings_python negative integer " -1234 to 4321- " and anycodings_python non-integer " 1.234 to 432.1". please help anycodings_python me. P.S. cannot use "str()" function

I just only can write the script to reverse anycodings_python positive integer 1234 to 4321

def reverse_int(n):

    x = 0
    while n > 0:
        x *= 10
        x += n % 10
        n /= 10
    return x
print reverse_int(1234)

Total Answers 7

24

Answers 1 : of python-How to reverse an negative integer or non-integer

def reve(x):
    x=str(x)
    if x[0]=='-':
        a=x[::-1]
        return f"{x[0]}{a[:-1]}"
    else:
        return x[::-1]

print(reve("abc"))
print(reve(123))
print(reve(-123))

#output cba 321 -321

0

2022-10-06T10:36:56+00:00 2022-10-06T10:36:56+00:00Answer Link

mRahman

5

Answers 2 : of python-How to reverse an negative integer or non-integer

how about using your code, but just anycodings_python-2.x concatenate a - when n is negative?

rev_int.py:

def reverse_int(m):
    x = 0
    n = m
    if m < 0 :
      n *= -1
    while n > 0 :
        x *= 10
        x += n % 10
        n /= 10
    if m < 0:
      #concatenate a - sign at the end
      return `x` + "-"
    return x

print reverse_int(1234)
print reverse_int(-1234)

This produces:

$ python rev_int.py
4321
4321-

0

2022-10-06T10:36:56+00:00 2022-10-06T10:36:56+00:00Answer Link

jidam

2

Answers 3 : of python-How to reverse an negative integer or non-integer

Using SLICING EASILY DONE IT

def uuu(num):
if num >= 0: 
    return int(str(num)[::-1])
else:
    return int('-{val}'.format(val = str(num)[1:][::-1]))

0

2022-10-06T10:36:56+00:00 2022-10-06T10:36:56+00:00Answer Link

miraj

1

Answers 4 : of python-How to reverse an negative integer or non-integer

Below code runs fine on Python-3 and anycodings_python-2.x handles positive and negative integer anycodings_python-2.x case. Below code takes STDIN and prints anycodings_python-2.x the output on STDOUT.

Note: below code handles only the anycodings_python-2.x integer case and doesn't handles anycodings_python-2.x the non-integer case.

def reverseNumber(number):
        x = 0
        #Taking absolute of number for reversion logic
        n = abs(number)
        rev = 0
        #Below logic is to reverse the integer
        while(n > 0):
            a = n % 10
            rev = rev * 10 + a
            n = n // 10
        #Below case handles negative integer case
        if(number < 0):
            return (str(rev) + "-")
        return (rev)
#Takes STDIN input from the user
number=int(input())
#Calls the reverseNumber function and prints the output to STDOUT
print(reverseNumber(number))

0

2022-10-06T10:36:56+00:00 2022-10-06T10:36:56+00:00Answer Link

joy

1

Answers 5 : of python-How to reverse an negative integer or non-integer

Using str convert method.

num = 123
print(str(num)[::-1])

0

2022-10-06T10:36:56+00:00 2022-10-06T10:36:56+00:00Answer Link

joy

2

Answers 6 : of python-How to reverse an negative integer or non-integer

Use this as a guide and make it work for anycodings_python-2.x floating point values as well:

import math

def reverse_int(n):
    if abs(n) < 10:
        v = chr(abs(n) + ord('0'))
        if n < 0: v += '-'
        return v
    else:
        x = abs(n) % 10
        if n < 0: return chr(x + ord('0')) + reverse_int(math.ceil(n / 10))
        else: return chr(x + ord('0')) + reverse_int(math.floor(n / 10))

print reverse_int(1234)

0

2022-10-06T10:36:56+00:00 2022-10-06T10:36:56+00:00Answer Link

miraj

4

Answers 7 : of python-How to reverse an negative integer or non-integer

Why not just do the following?:

def reverse(num):
    revNum = ''
    for i in `num`:
        revNum = i + revNum
    return revNum

print reverse(1.12345)
print reverse(-12345)

These would print 54321.1 and 54321-.

Lol, I don't understand the down-vote.. anycodings_python-2.x I guess this is too simple and doesn't anycodings_python-2.x require over complicating the process to anycodings_python-2.x get to the same result? Does this not anycodings_python-2.x solve the problem at hand no matter the anycodings_python-2.x number used?

0

2022-10-06T10:36:56+00:00 2022-10-06T10:36:56+00:00Answer Link

joy

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