The reason why this happens is because you are using commas in your print statements. In python there are a few ways to give the print statement multiple variables, you seem to be mixing two of them together. The ways are as follows.

• Concatenate the string.

  print('The ratio of ' + str(number1) + ' + ' + str(number2) + ' is ' + str(ration12) + '.')

  This way is probably the most basic way. It will join the strings without adding any characters in between them (e.g. no spaces in between unless you add them explicitly.) Also note, that string concatenation won't automatically cast the integers to a string for you.
• Pass print multiple arguments.

  print('The ratio of', number1, '+', number2, 'is', ration12, '.')

  This will automatically add spaces between each argument and is what is happening in your case. The separator (which defaults to a space) can be changed by passing a keyword argument to the print function. For example, print('i = ', i, sep='')
• Use string formatting.

  print('The ratio of {} + {} is {}.'.format(number1, number2, ratio12))

  This way is the most readable and often the best way. It will replace the '{}' sections in you 'template' string with the arguments based into the format function. It does this in order, however you can add an index like this '{0}' to explicitly use an argument by index.

By default, print puts spaces between each of the arguments it receives.

There are a number of ways you can get the behavior you want. Here are a few different options:

# The 'sep' argument changes what separator is used between args:
print("The length of your name is ", length, ".", sep='')

# String concatenation doesn't implicitly add any separators:
print("The length of your name is " + str(length) + ".")

# String formatting similarly lets you be more precise with your spacing:
print("The length of your name is {}.".format(length))
print(f"The length of your name is {length}.")

You need to concatenate it:

print first_name, "was born on", month, day+',', year, "."

UPDATE: as @sr2222 points out, this will print an extra space before the period. If you want to avoid it (and assuming that year is a string):

print first_name, "was born on", month, day+',', year + "."

Use string formatting:

print "i is equal to %d." % i

As of Python 2.6, strings have a .format() function that can alternatively be used:

>>> print "i is equal to {}".format(i)
i is equal to 5

It's useful if you have a placeholder that's used multiple times in the format string:

>>> print "i={0}, a.k.a. 'i is equal to {0}.'".format(i)
i=5, a.k.a. 'i is equal to 5.'

When you separate values with comma in print() it will add spaces. Since you are using Python 3 you could instead use f-strings like this

print(f"{name}, you were born in {year}.")

There's great documentation on it here: https://docs.python.org/3/tutorial/inputoutput.html#

Use an f string, just like this!

import datetime
from datetime import date
today = date.today()
user_name = input('What is your name? ')
user_age = int(input('How old are you? '))
print(f"Hello {user_name}! You were born in {today.year - user_age}.")

Just define a function to fix one sentence, then use list comprehension to construct a new list from the old:

def fix_sentence(str):
    if str == "":                    # Don't change empty strings.
        return str
    if str[-1] in ["?", ".", "!"]:   # Don't change if already okay.
        return str
    if str[-1] == ",":               # Change trailing ',' to '.'.
        return str[:-1] + "."
    return str + "."                 # Otherwise, add '.'.

orig_sentences = ['Hi how are you?', 'I am good', 'Great!', 'I am doing good,', 'Good.']
fixed_sentences = [fix_sentence(item) for item in orig_sentences]
print(fixed_sentences)

This outputs, as requested:

['Hi how are you?', 'I am good.', 'Great!', 'I am doing good.', 'Good.']

With a separate function, you can just improve fix_sentence() if/when new rules need to be added.

For example, being able to handle empty strings so that you don't get an exception when trying to extract the last character from them, as per the first two lines of the function.

Try this:

print ("{} + {} is equal to {}.".format(num1, num2, add(num1, num2)))

This makes use of the format() method documented here.

You can create a class. For this example, .myfunc() will return 1 if the number is greater than 0, otherwise, it will return 0:

class s:
    def __init__(self, value):
        self.value = value

    def myfunc(self):
        if self.value > 0:
            return 1
        else:
            return 0

num = s(20)

print(num.myfunc())

Output:

1