phililp:
pls someone help... whats the difference between mutable and immutable in python..


a detailed explanation will be highly appreciated

thanks

Immutable: the value stored in a variable can't be changed.
Mutable: the value stored in the variable can be changed.

Strings, dictionaries, tuples are immutable.
Lists are mutable.

We'd talk about them explicitly as we progress

.

.

4. Loops
When you try to perform a task more than once, Python has the capability of handling that task.
For example of you were to open about 10 files, then do some thing to them , then close. It would be easy for you to perform the task without a loop. But of you were given 100 000 files , now this would take you about 10 years to do it manually. So computers are very capable of performing a task severally and Python has that ability.

The first loop we'd be talking about is the WHILE LOOP.

We basically perform repetitions using loops.
In programming context it's called ITERATION.
That is to say line one does something, then it goes to line 2, line 2 them says the program shouldn't terminate then it returns to line1 again and performs that task.
So that circuit of movement is called an ITERATION.

Let's get to coding

count = 0
While count <=4:
print(count)
count += 1

0
1
2
3
4

Explanation of the above code
To use a while loop you have to initialize a counter. We intialized our counter to 0 so our loops would start from 0.
Our counter is count.
The counter also acts as an accumulator.
As the program makes on iteration 1 is added to count, which then stores it.
On the second iteration another 1 is added to account until it makes 5 iterations. So count also gets updated after an iteration.

Beware: when using a while loop always make sure the loop terminates unless it would keep on running till it overflows the stack.
This kind of loop is called an infinite loop. For example

i = 0
While i == 0:
print("infinite loop. This loop would continue to run" )

This loop would run without stopping because there's no condition that terminates this program.


def sequence (n):
while n != 1:
print(n)
if n % 2 == 0:
n = n/2
else:
n = n*3+1

Explanation:
We created a function called sequence with a ln argument n.

Until the value n is equal to 1 before it terminates. Since we said while n is not equal to one.
So if it's contrary it should stop.
If the n is even it is divided by 2 if it's false it is replaced by n*3+1.
If you pass 10 to the argument n the result would be: 3, 10, 5, 16, 8, 4, 2, 1.
When it gets to one the loop terminates.

But there's something really interesting and fascinating about this loop.
Actually there are 2 things that are interesting but the second is more.
1. This is an indefinite loop but it doesn't overflow the stack. The computation keeps on occuring until the condition is met.
There's no even any obvious proof that any would reach 1.
The number of iterations are unknown to us but we know it would terminate due to the expressions in the if and else statements.

2. It's impossible to prove that this program terminates for all positive values of n.
No one has been able to prove this.

You can go read about the collatz conjecture.

This code was gotten from Allen Downey's think Python textbook. A recommended one for you all.

.

NB: I'm also a learner in Python so all criticisms are welcome.At least it should be fair minded, objective and be borne out of a heart that seeks to make positive changes.

So if you see me asking questions in Python don't be amused because I'm also learning.

hello @stealthtinger I'm also a unilag student currently learn python, mind if I can meet with you in person?
if so, please send your number to ajayiolaniyi@gmail.com.
thanks



cc: stealthtinger

if you are interested in joining a Python Fellowship. then .... https:///KTkRJuHrxs36Zq5r5u6DAW

adejumoadeoluwa:
if you are interested in joining a Python Fellowship. then .... https:///KTkRJuHrxs36Zq5r5u6DAW

your link is not working

Python 3.(4).3 (v3.4.3:9b73f1c3e601, Feb 24 2015, 22:43:06) [MSC v.1600 32 bit (Intel)] on win32
Type "copyright", "credits" or "license()" for more information.

if i run it will telling me invalid syntax alighting the 4 with red.

please family wat is the solution to this.

opaniyi12:
Python 3.(4).3 (v3.4.3:9b73f1c3e601, Feb 24 2015, 22:43:06) [MSC v.1600 32 bit (Intel)] on win32
Type "copyright", "credits" or "license()" for more information.

if i run it will telling me invalid syntax alighting the 4 with red.

please family wat is the solution to this.

How many bits operating system are you using

i love your tutorial

Bro.. I'm a Unilag student too.. Can i meet u face to face for lectures?

stealthtiger:
.

bro.. I tried installing python and this is what it's saying

samyomz:
bro.. I tried installing python and this is what it's saying

I haven't come across this problem.
I think you should ask about this in programming forums.
Or just a Google search.
Hope you get it working to explore to beautiful world of Python

stealthtiger:

I haven't come across this problem.
I think you should ask about this in programming forums.
Or just a Google search.
Hope you get it working to explore to beautiful world of Python

I've already installed it bro.... Starting to learn it.. Although it's a lil bit confusing

samyomz:
I've already installed it bro.... Starting to learn it.. Although it's a lil bit confusing

Good bro.
Feel free to ask questions any where including nairaland there are smart Python programmers here

stealthtiger:

Good bro.
Feel free to ask questions any where including nairaland there are smart Python programmers here

Aii. .. Thanks

kechux:
Nice. Also look at this complete Phyton Trainning outline:

-Web Programming
-Network Programming
-Soft Development
-Scientific Computing
-GUI Library
-Excretion.

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Checkout my signature for contact details!

Nice training outline.
But it'd be better if you create a seperate thread to publicise it

*spreads mat*

Bro. abeg continue this thing

My sincere apologies for not being consistent with the tutorials. It was as a result of some circumstantial factors
Continuation of While loop
BREAK
There are sometimes when you'd want to end the loop after a certain condition has been met. The break statement is the perfect remedy for that.


count = 0
while count != 20:
print(count)
count +=1
if count == 5:
print("Hold up" )
break

Result:
0
1
2
3
4
Hold up

Explanation: the while says it'd keep running until count is equal to 20. But there's an if statement nested in the while loop which says it should BREAK when count is equal to 9 then print Hold up.
The break terminates the code prematurely.

There's also the CONTINUE statement.
Unlike the break statement, the continue performs an action for a condition and continues from where it stopped.

We'd make use of the example in the break statement

count = 0
while count != 20:
print(count)
count +=1
if count == 2:
print("I am 2" )
continue
if count == 6:
print("I am 6" )
continue
break
print("I didn't get to 20" )

Result:
0
1
I am 2
3
4
5
I am 6
I didn't get to 20


Explanation:
In this example we made use of the continue extensively.
We created the while loop and gave it an intializer 'count' which also acted as a variable.
The count was intialized to zero. ie. The loop will start from zero. We told the loop to progress by adding one to count.

When the loop is not equal to 20, we told it to keep running.
We then nested two if statements. In the first if: if count is equal to 2 the loop wouldn't print 2 instead it would print I am 2, then it would continue the loop into the next iteration (this is as a result of the continue. Unlike the break once it gets to 2 it automatically terminates but in continue it executes the statement and moves on).
When it gets to the break statement it terminates the loop prematurely.

FOR LOOP:

The for loop is used to iterate over a know range of something. Eg a list, a range of numbers. What the for loop iterates over is mostly definite.

stealthtiger:
My sincere apologies for not being consistent with the tutorials. It was as a result of some circumstantial factors
Continuation of While loop
BREAK
There are sometimes when you'd want to end the loop after a certain condition has been met. The break statement is the perfect remedy for that.


count = 0
while count != 20:
print(count)
count +=1
if count == 5:
print("Hold up" )
break

Result:
0
1
2
3
4
Hold up

Explanation: the while says it'd keep running until count is equal to 20. But there's an if statement nested in the while loop which says it should BREAK when count is equal to 9 then print Hold up.
The break terminates the code prematurely.

There's also the CONTINUE statement.
Unlike the break statement, the continue performs an action for a condition and continues from where it stopped.

We'd make use of the example in the break statement

count = 0
while count != 20:
print(count)
count +=1
if count == 2:
print("I am 2" )
continue
if count == 6:
print("I am 6" )
continue
break
print("I didn't get to 20" )

Result:
0
1
I am 2
3
4
5
I am 6
I didn't get to 20


Explanation:
In this example we made use of the continue extensively.
We created the while loop and gave it an intializer 'count' which also acted as a variable.
The count was intialized to zero. ie. The loop will start from zero. We told the loop to progress by adding one to count.

When the loop is not equal to 20, we told it to keep running.
We then nested two if statements. In the first if: if count is equal to 2 the loop wouldn't print 2 instead it would print I am 2, then it would continue the loop into the next iteration (this is as a result of the continue. Unlike the break once it gets to 2 it automatically terminates but in continue it executes the statement and moves on).
When it gets to the break statement it terminates the loop prematurely.

FOR LOOP:

The for loop is used to iterate over a know range of something. Eg a list, a range of numbers. What the for loop iterates over is mostly definite.

Boss, am a beginner in programming in which I need some advice and guideline fro u.

Don't mind if u can drop your WhatsApp/Phone no. Or better still, u can inbox am to my mail @ bashirzubair881@gmail.com
Pls I will be delighted if u can help me out wit this!!!

stealthtiger:
My sincere apologies for not being consistent with the tutorials. It was as a result of some circumstantial factors
Continuation of While loop
BREAK
There are sometimes when you'd want to end the loop after a certain condition has been met. The break statement is the perfect remedy for that.


count = 0
while count != 20:
print(count)
count +=1
if count == 5:
print("Hold up" )
break

Result:
0
1
2
3
4
Hold up

Explanation: the while says it'd keep running until count is equal to 20. But there's an if statement nested in the while loop which says it should BREAK when count is equal to 9 then print Hold up.
The break terminates the code prematurely.

There's also the CONTINUE statement.
Unlike the break statement, the continue performs an action for a condition and continues from where it stopped.

We'd make use of the example in the break statement

count = 0
while count != 20:
print(count)
count +=1
if count == 2:
print("I am 2" )
continue
if count == 6:
print("I am 6" )
continue
break
print("I didn't get to 20" )

Result:
0
1
I am 2
3
4
5
I am 6
I didn't get to 20


Explanation:
In this example we made use of the continue extensively.
We created the while loop and gave it an intializer 'count' which also acted as a variable.
The count was intialized to zero. ie. The loop will start from zero. We told the loop to progress by adding one to count.

When the loop is not equal to 20, we told it to keep running.
We then nested two if statements. In the first if: if count is equal to 2 the loop wouldn't print 2 instead it would print I am 2, then it would continue the loop into the next iteration (this is as a result of the continue. Unlike the break once it gets to 2 it automatically terminates but in continue it executes the statement and moves on).
When it gets to the break statement it terminates the loop prematurely.

FOR LOOP:

The for loop is used to iterate over a know range of something. Eg a list, a range of numbers. What the for loop iterates over is mostly definite.

Hi man, can we discuss a project on whatsapp?? Message me 08151097447

We are still sitted..waiting for the class to continue sir..Thank you for impacting us with knowledge..more power to your elbow...

I also prepared some awesome Python tutorials at www.coolpythoncodes.com

stealthtiger:
4. Loops
When you try to perform a task more than once, Python has the capability of handling that task.
For example of you were to open about 10 files, then do some thing to them , then close. It would be easy for you to perform the task without a loop. But of you were given 100 000 files , now this would take you about 10 years to do it manually. So computers are very capable of performing a task severally and Python has that ability.

The first loop we'd be talking about is the WHILE LOOP.

We basically perform repetitions using loops.
In programming context it's called ITERATION.
That is to say line one does something, then it goes to line 2, line 2 them says the program shouldn't terminate then it returns to line1 again and performs that task.

So that circuit of movement is called an ITERATION.

Let's get to coding

count = 0
While count <=4:
print(count)
count += 1

0
1
2
3
4

Explanation of the above code
To use a while loop you have to initialize a counter. We intialized our counter to 0 so our loops would start from 0.
Our counter is count.
The counter also acts as an accumulator.
As the program makes on iteration 1 is added to count, which then stores it.
On the second iteration another 1 is added to account until it makes 5 iterations. So count also gets updated after an iteration.

Beware: when using a while loop always make sure the loop terminates unless it would keep on running till it overflows the stack.
This kind of loop is called an infinite loop. For example

i = 0
While i == 0:
print("infinite loop. This loop would continue to run" )

This loop would run without stopping because there's no condition that terminates this program.


def sequence (n):
while n != 1:
print(n)
if n % 2 == 0:
n = n/2
else:
n = n*3+1

Explanation:
We created a function called sequence with a ln argument n.

Until the value n is equal to 1 before it terminates. Since we said while n is not equal to one.
So if it's contrary it should stop.
If the n is even it is divided by 2 if it's false it is replaced by n*3+1.
If you pass 10 to the argument n the result would be: 3, 10, 5, 16, 8, 4, 2, 1.
When it gets to one the loop terminates.

But there's something really interesting and fascinating about this loop.
Actually there are 2 things that are interesting but the second is more.
1. This is an indefinite loop but it doesn't overflow the stack. The computation keeps on occuring until the condition is met.
There's no even any obvious proof that any would reach 1.
The number of iterations are unknown to us but we know it would terminate due to the expressions in the if and else statements.

2. It's impossible to prove that this program terminates for all positive values of n.
No one has been able to prove this.

You can go read about the collatz conjecture.

This code was gotten from Allen Downey's think Python textbook. A recommended one for you all.

I really don't understand how passing 10 to the argument will give that result. when i ran the code, it keeps printing 10.
As i see it, we told it to print n while n != 1,

samyomz:
bro.. I tried installing python and this is what it's saying

install miniconda or anaconda.

please don't waste your time on python if you can't read html.

TheCabal:


install miniconda or anaconda.

please don't waste your time on python if you can't read html.

so before i can know python, i have to know html?

samyomz:
so before i can know python, i have to know html?

he is trolling on you bro.