Naming Conventions

Hello Martin, can you please explain why we have incrementors for a and b in the for loop that they are not being incremented why ‘a’ remains at 250 for the output ?

Hello @jasonwilliams78, I am not quite understanding what you’re asking. I think you are referring to the previous video about the Python Pub Quiz?

a, b = 250, 250

for _ in range(250, 260):
    if a is not b:
        break
    a += 1
    b += 1

print(a)

Both a and b are being incremented in this for loop, as long as they have the same id(). As soon as they refer to two different objects, the if statement catches and the loop breaks, which means they don’t get incremented anymore.

However, a should not be 250 at the output. Maybe you have a bug somewhere in your code?

thanks Martin!, I understand now. But yes I have 250 for the output. Using Jupyter notebook. Will check over it again

I tested the code in a Jupyter notebook, since who knows, maybe notebooks handle caching differently, but my output is as expected.

Take a look at your indentation and make sure that it matches the example above.

If it still shows 250 as output, maybe you can publish your notebook on GitHub so I can give your code a tryout.

I figured out why the output wasn’t accurate. I had the a,b incrementors set inside the local variable namespace. Once I moved them up one level to the for loop scope I they were both able to increment correctly.

a, b = 250, 250
for i in range(250,260):
    if a != b:
        break
    a += 1
    b += 1

print(a,b)

260 260

Good evening, Martin. Can you tell me if I have a valid solution to this. My code is below the instructions.

data = ((1,2),(3,4)) for i in data: i = sum(data[0]) i = sum(data[1]) print(f”row 1 sum: {row1}”) print(f”row 2 sum: {row2}”)

a , b = 250, 250

for i in range(250,260): if a is not b: break a += 1 b += 1

print(a)

My output is : 257

Could someone please help here? Am I missing something?

a , b = 250, 250 print(id(a)) print(id(b))

print(a is b)

for i in range(250,260): if a is not b: break a += 1 b += 1

print(a)

./test.py 139706676028128 139706676028128 True 257

Am I doing this right?

You’re doing it right @Ganesh. :)

Hello @Martin Breuss I am really new in Python, When I run the below steps : a, b = 250, 250 print(id(a)) print(id(b)) for _ in range(250,260): if a is not b: break a += 1 b += 1 print(a)

OUTPUT is : 251

BUT when I run below steps: a , b = 250, 250 print(id(a)) print(id(b))

for _ in range(250,260): if a is not b: break a += 1 b += 1

print(a)

OUTPUT is : 257

Why am I getting diffrent results when my both steps are almost same except indentation in second steps in a += 1 b += 1

Kindly guide. Thanks in advance.

Hello @kamjag. It’s difficult to tell since your code formatting isn’t clear. You can use triple-backticks for proper code formatting, like so:

def hello():
    print("hello")

If you post it again with proper formatting, I can take a closer look. But one thing to note is that indentation has meaning in Python. So whether a line of code is indented or not will make a difference in your code. Hope that helps!

Got answer as 257 and know the exact reason behind this. Thanks martin for wonderful explaination.

a, b = 250, 250

for _ in range(250, 258):
    print (f"Value of a {a}")        
    print (f"ID of a {id(a)}")
    print (f"Value of a {b}")
    print (f"ID of a {id(b)}")
    if a is not b:
        print (f"Value of a {a}")
        print (f"Value of a {b}")
        break
    a += 1
    b += 1
print (a)

**# Output

a = 300

b = a

print(id(a), id(b))

Only if I use different values for both the variables, I get different memory addresses for them. What is the issue here?

Hi @abp! In this case you’re literally making another reference to the same object. You’re saying something like:

a points to the integer object with the value 300. b points to a, which points to the integer object with the value 300.

Or, for a kinda textual-visual representation:

b ==> a ==> 300

tl;dr: You’re only creating one object, and pointing two variables to it.