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Python Set Operations Explained: From Theory to Real-Time Applications

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A  set  in Python is an unordered collection of unique elements. It is useful when storing distinct values and performing operations like union, intersection, or difference. Real-Time Example: Removing Duplicate Customer Emails in a Marketing Campaign Imagine you are working on an email marketing campaign for your company. You have a list of customer emails, but some are duplicated. Using a set , you can remove duplicates efficiently before sending emails. Code Example: # List of customer emails (some duplicates) customer_emails = [ "alice@example.com" , "bob@example.com" , "charlie@example.com" , "alice@example.com" , "david@example.com" , "bob@example.com" ] # Convert list to a set to remove duplicates unique_emails = set (customer_emails) # Convert back to a list (if needed) unique_email_list = list (unique_emails) # Print the unique emails print ( "Unique customer emails:" , unique_email_list) Ou...
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How to Decode TLV Quickly

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TLV format consists of three components: Tag, Length, and Value. In credit card and financial transactions, the TLV protocol utilizes this structure. Below, you will find tips for quickly decoding TLV data. 


TLV Format



According to IBM, the tag tells what type of data it is. The length field denotes the length of the value, and the value is the actual value.


Structure of TLV.


TLV comprises three field values.


  1. Tag
  2. Length
  3. Value


How to Decode TLV


The EMV labs developed tags that are part of the EMV protocol. Each tag has a unique meaning. The Tag and Length together take 1 to 4 bytes of memory.

1. The Best example for TLV.


Below is the method for decoding the EMV tag. The first part of the TLV format is TAG. The second part is LENGTH, and finally, the value.


Syntax of EMV tag:


[Tag][Value Length][Value] (ex. "9F4005F000F0A001")


where, 


Tag Name = 9F40


Value Length (in bytes) = 05 


Value (Hex representation of bytes. Example, "F0" – 1-byte) = F000F0A001


Finally, what is 9F40 tag? The EMV company assigns a value to it. Check out the complete list of EMV Tags and meanings.



2. How to read the TLV


Let me elaborate on the memory the EMV tag takes. The breakup of memory allocation is as follows.

 

Tag: 1 or 2 bytes.


Length: 05


Value length:


F0-00-F0-A0-01 ==> 5 Bytes


The F0 is the HEX value of length 1. So the total length of the value altogether is 5 bytes.


F0+00+F0+A0+01= Total 5 bytes



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