Difference between revisions of "Python/C3/Loops/English-timed"

From Script | Spoken-Tutorial
Jump to: navigation, search
Line 10: Line 10:
 
| 00:05
 
| 00:05
 
| At the end of this tutorial, you will be able to,
 
| At the end of this tutorial, you will be able to,
 
+
use the  '''for''' loop
# use the  '''for''' loop
+
use the '''while''' loop
# use the '''while''' loop
+
Use '''break''', '''continue''' and '''pass''' statements to play around with loops.
# Use '''break''', '''continue''' and '''pass''' statements to play around with loops.
+
  
 
|-
 
|-
Line 41: Line 40:
 
|-
 
|-
 
|00:45
 
|00:45
|Type i = 1
+
|Type i = 1 while i less than 10 colon print i multiply by i, i += 2
 
+
while i less than 10 colon
+
    print i multiply by i
+
    i += 2
+
  
 
|-
 
|-
Line 73: Line 68:
 
|-
 
|-
 
|01:58
 
|01:58
|Type i = 2
+
|Type i = 2, while i less than 10 colon print i multiply by i i += 2
 
+
  while i less than 10 colon
+
    print i multiply by i
+
    i += 2
+
  
 
|-
 
|-
Line 93: Line 84:
 
|-
 
|-
 
|02:48
 
|02:48
|Type for n in range within bracket 1 comma 10 comma 2 colon
+
|Type for n in range within bracket 1 comma 10 comma 2 colon. print n multiply by n
      print n multiply by n
+
  
 
|-
 
|-
Line 118: Line 108:
 
|-
 
|-
 
| 03:26
 
| 03:26
|Type for n in range within bracket 2 comma 10 comma 2 colon
+
|Type for n in range within bracket 2 comma 10 comma 2 colon. print n multiply by n
        print n multiply by n
+
  
 
|-
 
|-
Line 135: Line 124:
 
|-
 
|-
 
|04:02
 
|04:02
|Type for n in range within bracket 2 comma 10 comma 2 colon
+
|Type for n in range within bracket 2 comma 10 comma 2 colon pass And Enter.
 
+
    pass
+
 
+
    And Enter.
+
  
 
|-
 
|-
Line 151: Line 136:
 
|-
 
|-
 
|04:31
 
|04:31
|Type = 1
+
|Type = 1,while True colon print i multiply by i   i += 2   if i is less than 10 colon break
 
+
while True colon
+
    print i multiply by i
+
    i += 2
+
    if i is less than 10 colon
+
    break
+
 
|-
 
|-
 
|05:10
 
|05:10
 
|So we got a syntax error because 'if' is not inside the while loop
 
|So we got a syntax error because 'if' is not inside the while loop
So type while True colon
+
So type while True colon
    print i multiply by i
+
print i multiply by i
    i += 2
+
i += 2
    if i less than 10 colon
+
if i less than 10 colon
        break
+
break
 
Make sure that 'if' is inside the while loop.
 
Make sure that 'if' is inside the while loop.
  
Line 179: Line 158:
 
|06:03
 
|06:03
 
|So, in terminal, Type for n in range within bracket 1 comma 10 comma 2 colon
 
|So, in terminal, Type for n in range within bracket 1 comma 10 comma 2 colon
 
+
if n modulo 3 == 0 colon
    if n modulo 3 == 0 colon
+
continue
        continue
+
print n multiply by n
    print n multiply by n
+
  
 
|-
 
|-
Line 194: Line 172:
 
|-
 
|-
 
|  06:53
 
|  06:53
| (Do not modify the range function call.)
+
| (Do not modify the range function call.)
  
 
|-
 
|-
Line 203: Line 181:
 
|07:02
 
|07:02
 
|Type for n in range within bracket 2 comma 10 comma 2 colon
 
|Type for n in range within bracket 2 comma 10 comma 2 colon
    if n modulo 4 colon
+
if n modulo 4 colon
        continue
+
continue
    print n multiply by n
+
print n multiply by n
  
 
|-
 
|-
Line 213: Line 191:
 
|-
 
|-
 
|  07:33
 
|  07:33
|  In this tutorial, we have learnt to, 1. Iterate over a sequence using ``for'' and ``while'' loops.
+
|  In this tutorial, we have learnt to, Iterate over a sequence using ``for'' and ``while'' loops.
 
    
 
    
 
|-
 
|-
 
|  07:38
 
|  07:38
| 2. Break out of loops using ``break'' statement.
+
|Break out of loops using ``break'' statement.
  
 
|-
 
|-
 
|  07:42
 
|  07:42
| 3. Skip iterations using ``continue'' statement.
+
|Skip iterations using ``continue'' statement.
  
 
|-
 
|-
 
|  07:45
 
|  07:45
| 4. Use the ``pass'' statement in a loop.
+
|Use the ``pass'' statement in a loop.
  
 
|-
 
|-
Line 233: Line 211:
 
|-
 
|-
 
|  07:52
 
|  07:52
| 1. Given  range(1 comma 4) ; Write a code to print only the number 1.  
+
|Given  range(1 comma 4) ; Write a code to print only the number 1.  
  
 
|-
 
|-
 
|  08:01
 
|  08:01
| 2.Second one is, Which statement do you use to skip iterations. - break - pass - continue
+
|Second one is, Which statement do you use to skip iterations. - break - pass - continue
  
 
|-
 
|-
Line 245: Line 223:
 
|-
 
|-
 
|  08:12
 
|  08:12
| 1. First one, We can use the break statement in a for loop as,
+
| First one, We can use the break statement in a for loop as,''' colon colon'''
''' colon colon'''
+
  
 
|-
 
|-

Revision as of 16:49, 20 February 2017

Time Narration
00:01 Hello Friends and Welcome to the tutorial on 'loops' in Python.
00:05 At the end of this tutorial, you will be able to,

use the for loop use the while loop Use break, continue and pass statements to play around with loops.

00:17 Before beginning this tutorial,we would suggest you to complete the tutorial on "Getting started with for" and "Conditionals".
00:24 Let us start our ipython interpreter.
00:28 Type ipython in the terminal
00:32 We shall first begin with the while loop.
00:34 The while loop is used for repeated execution as long as a condition is True .
00:39 Let us print the squares of all the odd numbers less than 10, using the while loop.
00:45 Type i = 1 while i less than 10 colon print i multiply by i, i += 2
01:19 This loop prints the squares of the odd numbers below 10.
01:23 The while loop, repeatedly checks if the condition is true and executes the block of code within the loop, if it is.
01:30 As with any other block in Python, the code within the while block is indented to the right by 4 spaces.
01:41 Pause the video here, try out the following exercise and resume the video.
01:48 Write a while loop to print the squares of all the even numbers below 10.
01:55 Switch to the terminal for solution.
01:58 Type i = 2, while i less than 10 colon print i multiply by i i += 2
02:27 Let us now solve the same problem of printing the squares of all odd numbers less than 10, using the for loop.
02:34 As we know, the for loop iterates over a list or any other sequential data type.
02:40 So, we use the range function to get a list of odd numbers below 10, and then iterate over it and print the required stuff.
02:48 Type for n in range within bracket 1 comma 10 comma 2 colon. print n multiply by n
03:07 We can see that we got the same output as before.
03:10 Note that the lines of code are less.
03:13 Pause the video here, try out the following exercise and resume the video.
03:19 Write a for loop to print the squares of all the even numbers below 10.
03:24 Switch to the terminal
03:26 Type for n in range within bracket 2 comma 10 comma 2 colon. print n multiply by n
03:46 Let us now look at how to use the keywords, pass , break and continue .
03:52 As we already know, pass is just a syntactic filler.
03:56 It is used for the sake of completion of blocks, that do not have any code within them.
04:02 Type for n in range within bracket 2 comma 10 comma 2 colon pass And Enter.
04:20 break is used to break out of the innermost loop.
04:24 The while loop to print the squares of all the odd numbers below 10, can be modified using the break statement, as follows
04:31 Type = 1,while True colon print i multiply by i i += 2 if i is less than 10 colon break
05:10 So we got a syntax error because 'if' is not inside the while loop

So type while True colon print i multiply by i i += 2 if i less than 10 colon break Make sure that 'if' is inside the while loop.

05:42 continue is used to skip execution of the rest of the loop on this iteration and continue to the end of this iteration.
05:50 So, we wish to print the squares of all the odd numbers below 10, which are not multiples of 3, we would modify the for loop as follows.
06:03 So, in terminal, Type for n in range within bracket 1 comma 10 comma 2 colon

if n modulo 3 == 0 colon continue print n multiply by n

06:36 Now Pause the video here, try out the following exercise and resume the video.
06:41 Using the continue keyword modify the for loop, with the range(2 comma 10 comma 2) , to print the squares of even numbers below 10, which are multiples of 4.
06:53 (Do not modify the range function call.)
06:59 Now Switch to the terminal for solution.
07:02 Type for n in range within bracket 2 comma 10 comma 2 colon

if n modulo 4 colon continue print n multiply by n

07:30 This brings us to the end of this tutorial.
07:33 In this tutorial, we have learnt to, Iterate over a sequence using ``for and ``while loops.
07:38 Break out of loops using ``break statement.
07:42 Skip iterations using ``continue statement.
07:45 Use the ``pass statement in a loop.
07:49 Here are some self assessment questions for you to solve
07:52 Given range(1 comma 4) ; Write a code to print only the number 1.
08:01 Second one is, Which statement do you use to skip iterations. - break - pass - continue
08:10 And the answers,
08:12 First one, We can use the break statement in a for loop as, colon colon
08:21 for i in range within bracket 1 comma 4 colon
08:27 Then print i break
08:30 And second one, In order to skip iterations,we make use of the continue statement.
08:37 Hope you have enjoyed this tutorial and found it useful.

Contributors and Content Editors

Gaurav, Kavita salve, Minal, PoojaMoolya, Sneha