# Words by the Numbers 3, Exercise 1: a letter-frequency table for a short invented passage.
import re
from collections import Counter

text = (
    "The lighthouse keeper climbed the stairs every evening to light the lamp, "
    "and the ships that passed in the dark steered by its steady beam."
)
letters = re.findall(r"[a-z]", text.lower())
counts = Counter(letters)
total = len(letters)
print("letters:", total, "| even-spread share:", f"{1 / 26:.1%}")
for letter, n in counts.most_common(5):
    print(f"{letter} {n:3d} {n / total:6.1%}")
print("e share:", f"{counts['e'] / total:.1%}", "| letters never used:", 26 - len(counts))

# Output when run (Python 3.14; the documentation-text figures depend on the Python version):
# letters: 113 | even-spread share: 3.8%
# e  20  17.7%
# t  14  12.4%
# h  10   8.8%
# s  10   8.8%
# i   8   7.1%
# e share: 17.7% | letters never used: 6