Python code help needed

I have to create a program using a for loop to print out all the possible 4 digit combinations to open a safe. Could anyone help me with the code please for this

Reply 1

Sonicalireza

How much do you know so far about for loops and how you’re going to code this overall?

Reply 2

Lauren12311

Literally started learning python about 2 weeks ago so my knowledge is literally as basic as it gets. All the question says is to “ write a program using a for loop to print out the four digit numbers that could be the safe combination”

Reply 3

Sonicalireza

Original post by Lauren12311

Ok so I’m not sure how complex of a solution it wants but essentially I’m guessing all it wants is for the program to print all numbers from 0 to 9999 and a for loop would make it repeat as many times as you want it to (in this case 9999 times) so the code would just be a for loop that starts by printing 0 then 1,2,3....9998,9999 and it repeats 9999 times,
You can just call the first variable x and make it =0 then in the loop it just adds one everytime and also prints it (I’m hoping you can try to figure it out since I don’t want to give the answer right away)

(edited 5 years ago)

Reply 4

Lauren12311

Thank you so much you’re a star I’ll give that a go. And then try and add the functions I worked out before in

Reply 5

smithb

Nested loops - 7 lines. The dots are to show indentation.

solutions = []
for i in range(10):
....for j in range(10):
........for k in range(10):
............for l in range(10):
................solutions.append(str(str(i) + str(j) + str(k) + str(l)))
print (solutions)

Alternative solution - str.zfill(4) means this can be done in 4 lines.

solutions = []
for i in range(10000):
....solutions.append(str(i).zfill(4))
print (solutions)

Tag me if you find any errors, would like more explanation, or find a cooler solution

edit - Previous solution can be condensed to 1 line :biggrin:

print ([str(x).zfill(4) for x in range(10000)])

(edited 5 years ago)

Reply 6

Lauren12311

Thank you @smithb after solutions = I got a invalid syntax is there a way to fix this

Reply 7

smithb

Original post by Lauren12311

Thank you @smithb after solutions = I got a invalid syntax is there a way to fix this

Try fully typing out the second solution, and replacing the dots with a tab. :smile:

Reply 8

Lauren12311

Replaced dots with tabs but the solutions still has an invalid syntax I’m on python 3.7 if that makes a difference @smithb

(edited 5 years ago)

Reply 9

smithb

Original post by Lauren12311

Replaced dots with tabs but the solutions still has an invalid syntax I’m on python 3.7 if that makes a difference

They are square brackets if that helps. Send me a screenshot of your code / error message?

Reply 10

Lauren12311

Original post by smithb

They are square brackets if that helps. Send me a screenshot of your code / error message?

Thank you so much it worked I completely missed the brackets 🤦🏽*♀️ told you I’m a beginner don’t even know what a for loop is

Reply 11

smithb

Original post by Lauren12311

Thank you so much it worked I completely missed the brackets 🤦🏽*♀️ told you I’m a beginner don’t even know what a for loop is

Happy to help :u:

Make sure you understand the code yourself though - shoot me with any questions whenever :biggrin:

Reply 12

Lauren12311

Original post by smithb

Happy to help :u:

Make sure you understand the code yourself though - shoot me with any questions whenever :biggrin:

For definite gonna try add in some functions to it now watch this fail 😂

Reply 13

Lauren12311

Original post by Lauren12311

For definite gonna try add in some functions to it now watch this fail 😂

Last question sorry to be a pain. Using the code you sent is there a way to add my function so it only returns numbers that are perfect squares? @smithb

(edited 5 years ago)

Reply 14

shivampaw

Original post by Lauren12311

Last question sorry to be a pain. Using the code you sent is there a way to add my function so it only returns numbers that are perfect squares? @smithb

Use an if statement before the append to check if i is a square number.


root = math.sqrt(i)
if int(root + 0.5) ** 2 == i:
    # append line here

You’ll need to import math as well at the top

Reply 15

Lauren12311

Original post by shivampaw

Use an if statement before the append to check if i is a square number.


root = math.sqrt(i)
if int(root + 0.5) ** 2 == i:
    # append line here

You’ll need to import math as well at the top

Thank you so much

Reply 16

smithb

Original post by Lauren12311

Last question sorry to be a pain. Using the code you sent is there a way to add my function so it only returns numbers that are perfect squares? @smithb

solutions = []

def isSquare(x):
....if (x**0.5) % 1 == 0:
........return True

for i in range(10000):
...if isSquare(i):
........solutions.append(str(i).zfill(4) )

print (solutions)

Reply 17

Lauren12311

Thank you kindly you’re a pro at this