تبدیل عدد به رشته در پایتون

Python 3.10.1 (tags/v3.10.1:2cd268a, Dec  6 2021, 19:10:37) [MSC v.1929 64 bit (AMD64)] on win32
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num_students = 7
"there is" + num_students + "students."
Traceback (most recent call last):
  File "<pyshell#1>", line 1, in <module>
    "there is" + num_students + "students."
TypeError: can only concatenate str (not "int") to str
"there is" + str(num_students) + "students."
'there is7students.'
"there is " + str(num_students) + " students."
'there is 7 students.'
"there is " + str(7) + " students."
'there is 7 students.'
num1 = 8
num2 = 3
"test " + str(num1 - num2) + " eol"
'test 5 eol'
"test " + str(num2 - num1) + " eol"
'test -5 eol'