🔒 Regular Expressions

[slate ivy]

Working on A code in Regular Expressions
The Problem Statement is to check if a Mobile numbe is Valid or Not based on :-

1. We want An 11 or 12 Digit Number
   11 if it starts with 0
   12of it starts with 91
2. We want the 3rd Digit to be either **6 or 7 or 8 or 9 **so from 6-9
3. We want the remaining 9 digits anything from 0-9
   Our Final Number should have 11 or 12 Digits only

Attaching Pastebin link for the Code
https://pastebin.com/GR7DwntR

[burnt sluice]

@slate ivy

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[agile rover]

not sure I understand how the 9 or 91 is used here...

it should start with 6-9 but also 91?

how is that possible?

are there examples?

[slate ivy]

9169876543210

Uhh sorry I copy posted it without correcting it

We want 12 or 11 Digit Number

Either Starting with 91 or 0

Then the third digit should be 6 or 7 or 8 or 9

Followed by the remaining last 9 digits that can be anything from 0-9

So

1. We want An 11 or 12 Digit Number
   11 if it starts with 0
   12 of it starts with 91
2. We want the 3rd Digit 6 or 7 or 8 or 9
3. We want the remaining 9 digits anything from 0-9
   Our Final Number should have 11 or 12 Digits only

[slate ivy]

is this bettter ?

[agile rover]

perfect, thanks

when you want an "or" situation in regex, you use |

so starting with a 0 or 91 would be (0|91)

[slate ivy]

Could you help me with the Rest of it too

[agile rover]

you basically have it, but you've thrown a lot of extra () at it for some reason

you can remove just about all of those

other than the ones around (0|91)

[slate ivy]

I get it

My issue is that I can't seem to be able to Hold it True when I want it for Exact 11 or 12 Digits

Like if you see the Number I have taken it Ends with 000

That being the case it should be False so My output should Invalid

[agile rover]

you can "anchor" a string to the start or end by using ^ and $

or you can use re.match instead (which basically does the anchoring for you)

[slate ivy]

I have done as you've said

I think it's matching the conditions till it finds true

Like you go grab a chocolate at a Departmental store

[agile rover]

re.search will search the entire string for a pattern.
re.match ensures the ENTIRE string is the pattern

[slate ivy]

Only in My case the store should only have a chocolate

Is that so ?

[agile rover]

let's see your updated code

[agile rover]

you still have extra () in there

it should be (0|91) to check for either of those at the start of the string

followed by [6-9]

followed by [0-9]{9}

which can be simplified to \d{9}

you don't need every single character in []

don't do [0], don't do [9]

[slate ivy]

Got You

like this ---->"(0|91)[6-9]\d{9}"

[agile rover]

exactly 🙂

[slate ivy]

done that

[agile rover]

and then either re.match, or re.search but with ^(0|91)[6-9]\d{9}$

[slate ivy]

I have simplified the code as you've said

[agile rover]

and is it not working?

[slate ivy]

It works for case 2---> re.search with ^(0|91)[6-9]\d{9}$

but for case 1

[agile rover]

does it show which cases fail?

[slate ivy]

this is what it shows

My Output should be invalid right

[agile rover]

!e

import re

num = '91612345678900'

print(re.match(r'^(0|91)[6-9]\d{9}$', num))

[burnt sluice]

:white_check_mark: Your 3.12 eval job has completed with return code 0.

None

[agile rover]

something is funky with that test

because it doesn't match here

[broken lark]

$ missing

[agile rover]

ahh yeah I was looking at their commented line, haha

also sorry I was slightly wrong about re.match. It doesn't check that the entire string is a match. It just anchors from the start

[slate ivy]

Okay Got it

so i need to include the '$' sign at the end in re.match

and for re.search i need to include the ^ sign at the beginning of the pattern

[broken lark]

both ^ and $ in re.search

[agile rover]

if you use both ^ and $, then it shouldn't really matter which one you use

[broken lark]

or re.fullmatch also exists

[slate ivy]

Yess Thank you so Much

Thank You So Much @agile rover and @broken lark

I implemented both cases

[slate ivy]

Will Implement this too

Done ✅ Implemented

@broken lark Were you saying something

[broken lark]

not really. except I may have wanted to comment that re.search and re.match have some difference in behaviour of the ^ only when "multiline" mode is used. But since you're not using that, I thought it wasn't worth commenting it 🙂

https://docs.python.org/3/library/re.html#search-vs-match

[slate ivy]

Ohh

Could You recommend me few books and learning resources for Python

I am quite a newbie to programming

[broken lark]

!resources

[burnt sluice]

Resources

The Resources page on our website contains a list of hand-selected learning resources that we regularly recommend to both beginners and experts.

[broken lark]

I don't really know any specific resource myself, as I acquired stuff over the years from all sorts of sources

[slate ivy]

In the sense that I was on a hiatus for about 2 years and have recently started to learn programming once again

[slate ivy]

Please Do Not say that

I may have a surface level perspective but your Knowledge seems pretty thorough

That doesn't just come from here and there

You're good That's True

[broken lark]

yea sure, but any resource I used when I was a beginner, was during a time where python 3 didn't even exist yet.. probably. 😄

[slate ivy]

Really !!!

[broken lark]

the most common resource I use is just the regular python docs.

(or the docs of any library I use)

[slate ivy]

That's like more than 15 years ago

U are a seasoned pro in that cade

[broken lark]

sounds about right, year-wise.

[slate ivy]

Do You mean the official website

The documentation there

[broken lark]

docs.python.org, yes

[slate ivy]

Ohh I was referring that today for RE

It was good

Would Definitely appreciate a cleaner UI though

Is it hard to transition from 2.0 to 3.0

[broken lark]

it's one of the cleanest and nicest docs I've ever seen, honestly 😄

[agile rover]

Pretty much all regex I've picked up has been from helping people out in these threads

I rarely use it personally

[slate ivy]

Woww

[agile rover]

but being curious enough to want to know the answer

[slate ivy]

You are awesome

[broken lark]

same for me with stuff like pandas and pygame, and so on

[slate ivy]

My first time using that documentation

[agile rover]

regex101 is also a great resource

[slate ivy]

That is so beautiful

I really hope to learn from you

Thank You So Much Both of You @broken lark @agile rover

Bye Bye

[burnt sluice]

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