Text File Programs (Board Pattern)

# Create the sample file used by all programs below
text = """The sun rises in the east.
Early birds catch the worm.
My school is near the river.
A good book is a best friend.
Time and tide wait for none.
"""
with open('story.txt', 'w') as f:
    f.write(text)
print('story.txt created with', text.count('\n'), 'lines')

The sun rises in the east.
Early birds catch the worm.
My school is near the river.
A good book is a best friend.
Time and tide wait for none.

# 1. Count characters, words and lines
def count_all():
    with open('story.txt') as f:
        data = f.read()
    print('Characters:', len(data))
    print('Words     :', len(data.split()))
    print('Lines     :', len(data.splitlines()))
count_all()

# 2. Count the word "the" (any case, ignoring punctuation)
def count_the():
    count = 0
    with open('story.txt') as f:
        for word in f.read().split():
            if word.strip('.,!?').lower() == 'the':
                count += 1
    print('"the" occurs', count, 'times')
count_the()

# 3. Display lines starting with 'T' and count them
def lines_with_T():
    n = 0
    with open('story.txt') as f:
        for line in f:
            if line[0] == 'T':
                print(line, end='')
                n += 1
    print('Total:', n)
lines_with_T()

# 4. Count vowels, consonants, uppercase and lowercase letters
def letters():
    v = c = up = low = 0
    with open('story.txt') as f:
        for ch in f.read():
            if ch.isalpha():
                if ch.lower() in 'aeiou':
                    v += 1
                else:
                    c += 1
                if ch.isupper():
                    up += 1
                else:
                    low += 1
    print('Vowels:', v, 'Consonants:', c, 'Upper:', up, 'Lower:', low)
letters()

# 5. Display words with fewer than 4 characters
def short_words():
    with open('story.txt') as f:
        words = [w.strip('.,') for w in f.read().split()]
    print([w for w in words if len(w) < 4])
short_words()

# 6. Count "Me" and "My" words (classic board question)
def me_my():
    count = 0
    with open('story.txt') as f:
        for w in f.read().split():
            if w.strip('.,') in ('Me', 'My', 'me', 'my'):
                count += 1
    print('Count of Me/My:', count)
me_my()

# 7. Copy lines NOT starting with a vowel into another file
def copy_lines():
    with open('story.txt') as src, open('result.txt', 'w') as dst:
        for line in src:
            if line[0].lower() not in 'aeiou':
                dst.write(line)
    with open('result.txt') as f:
        print(f.read(), end='')
copy_lines()

# 8. Longest line and line numbers
def longest():
    with open('story.txt') as f:
        lines = f.readlines()
    for i, line in enumerate(lines, 1):
        print(i, len(line.strip()), line.strip())
    big = max(lines, key=len)
    print('Longest:', big.strip())
longest()

# 9. Replace a word and save the file
def replace_word(old, new):
    with open('story.txt') as f:
        data = f.read()
    with open('story_new.txt', 'w') as f:
        f.write(data.replace(old, new))
    with open('story_new.txt') as f:
        print(f.readline(), end='')
replace_word('sun', 'moon')

# 10. Display each line in reverse and words in reverse order
with open('story.txt') as f:
    for line in f.readlines()[:2]:
        line = line.strip()
        print(line[::-1], '|', ' '.join(line.split()[::-1]))

# 11. Count frequency of each word
freq = {}
with open('story.txt') as f:
    for w in f.read().lower().split():
        w = w.strip('.,')
        freq[w] = freq.get(w, 0) + 1
top = sorted(freq.items(), key=lambda kv: (-kv[1], kv[0]))[:3]
print(top)

# 12. Count lines ending with a full stop and remove blank lines
with open('mixed.txt', 'w') as f:
    f.write('Hello.\n\nPython is fun\n\nBye.\n')
with open('mixed.txt') as f:
    lines = [l for l in f if l.strip()]
print('Non-blank lines:', len(lines))
print('Ending with "." :', sum(1 for l in lines if l.rstrip().endswith('.')))