58 lines
2.3 KiB
Python
58 lines
2.3 KiB
Python
"""
|
|
©AngelaMos | 2026
|
|
constants.py
|
|
|
|
Shared constants for the Caesar cipher: alphabet definitions and English letter frequency data
|
|
|
|
Defines the letter sets used by the cipher for case-aware shifting,
|
|
the expected frequency percentages for each English letter (used by
|
|
frequency analysis to score decryption candidates), and the chi-squared
|
|
threshold for filtering results.
|
|
|
|
Connects to:
|
|
cipher.py - imports UPPERCASE_LETTERS, LOWERCASE_LETTERS, ALPHABET_SIZE
|
|
analyzer.py - imports ENGLISH_LETTER_FREQUENCIES
|
|
"""
|
|
|
|
import string
|
|
from typing import Final
|
|
|
|
|
|
UPPERCASE_LETTERS: Final[str] = string.ascii_uppercase
|
|
LOWERCASE_LETTERS: Final[str] = string.ascii_lowercase
|
|
ALL_LETTERS: Final[str] = UPPERCASE_LETTERS + LOWERCASE_LETTERS
|
|
|
|
ALPHABET_SIZE: Final[int] = 26
|
|
|
|
ENGLISH_LETTER_FREQUENCIES: Final[dict[str,
|
|
float]] = {
|
|
"E": 12.70,
|
|
"T": 9.06,
|
|
"A": 8.17,
|
|
"O": 7.51,
|
|
"I": 6.97,
|
|
"N": 6.75,
|
|
"S": 6.33,
|
|
"H": 6.09,
|
|
"R": 5.99,
|
|
"D": 4.25,
|
|
"L": 4.03,
|
|
"C": 2.78,
|
|
"U": 2.76,
|
|
"M": 2.41,
|
|
"W": 2.36,
|
|
"F": 2.23,
|
|
"G": 2.02,
|
|
"Y": 1.97,
|
|
"P": 1.93,
|
|
"B": 1.29,
|
|
"V": 0.98,
|
|
"K": 0.77,
|
|
"J": 0.15,
|
|
"X": 0.15,
|
|
"Q": 0.10,
|
|
"Z": 0.07,
|
|
}
|
|
|
|
CHI_SQUARED_THRESHOLD: Final[float] = 50.0
|