Caesar Cipher Encoding Function | Dataford Interview Questions

Next Insurance uses lightweight text transformations in internal policy-processing tools. Implement a Caesar cipher encoder that shifts every English alphabetic character by a specified amount while preserving the original letter case.

Formal Specification

Implement encrypt_message(text, shift):

text is a string containing ASCII letters, digits, spaces, punctuation, and possibly other characters.
shift is an integer and may be positive, zero, or negative.
Shift uppercase letters within A-Z and lowercase letters within a-z, wrapping around at the end of each alphabet.
Leave digits, whitespace, punctuation, and all non-ASCII-letter characters unchanged.
Return the encoded string.

The shift may be larger than 26, so reduce it modulo 26. The input string must not be modified in place.

Constraints

0 <= len(text) <= 10^5
-10^9 <= shift <= 10^9
Letters in the input are restricted to ASCII A-Z and a-z
Digits, whitespace, punctuation, and other characters must be preserved

Function Signature

def encrypt_message(text, shift):

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