Practise indexing and slicing strings, string methods like split, join, strip and replace, and formatting output with f-strings.
Review first: Strings
Given full_name = "asha devi rao", print the initials in capitals with dots, like A.D.R.
split() gives a list of words. Take word[0] from each and use upper().
full_name = "asha devi rao"
initials = "".join(word[0].upper() + "." for word in full_name.split())
print(initials)A.D.R.Count how many vowels (a, e, i, o, u, in either case) are in text = "Python Is Easy To Learn".
Loop over text.lower() and check if ch in "aeiou".
text = "Python Is Easy To Learn"
count = 0
for ch in text.lower():
if ch in "aeiou":
count += 1
print(count)7A shorter version is sum(1 for ch in text.lower() if ch in "aeiou").
A palindrome reads the same backwards. Ignoring case and spaces, print whether each of "Racecar", "Never odd or even" and "Python" is a palindrome.
Clean the string with .lower() and .replace(" ", ""), then compare it with its reverse, s[::-1].
def is_palindrome(text):
cleaned = text.lower().replace(" ", "")
return cleaned == cleaned[::-1]
for phrase in ["Racecar", "Never odd or even", "Python"]:
print(phrase, "->", is_palindrome(phrase))Racecar -> True
Never odd or even -> True
Python -> FalseClean raw = " hello WORLD, welcome to PYTHON " so it prints as Hello World, Welcome To Python, with single spaces and no spaces at the ends.
split() with no argument splits on any run of spaces and drops the empty pieces. Then " ".join() and .title().
raw = " hello WORLD, welcome to PYTHON "
cleaned = " ".join(raw.split()).title()
print(cleaned)Hello World, Welcome To PythonReverse the order of the words in sentence = "practice makes progress", giving progress makes practice.
Split into a list of words, reverse the list, and join it back together.
sentence = "practice makes progress"
words = sentence.split()
reversed_sentence = " ".join(reversed(words))
print(reversed_sentence)progress makes practiceGiven email = "asha.rao@example.com", keep the first letter and the domain, and replace the rest of the name with *, giving a*******@example.com.
email.split("@") separates the name from the domain. "*" * n repeats a character n times.
email = "asha.rao@example.com"
name, domain = email.split("@")
masked = name[0] + "*" * (len(name) - 1) + "@" + domain
print(masked)a*******@example.comPrint these items as an aligned receipt: names left-aligned in 10 characters, prices right-aligned in 8 characters with 2 decimals, and a total line.
items = [("Tea", 30), ("Sandwich", 85.5), ("Cake", 120)]
In an f-string, {name:<10} left-aligns in 10 characters and {price:>8.2f} right-aligns a number with 2 decimals.
items = [("Tea", 30), ("Sandwich", 85.5), ("Cake", 120)]
total = 0
for name, price in items:
print(f"{name:<10}{price:>8.2f}")
total += price
print("-" * 18)
print(f"{'Total':<10}{total:>8.2f}")Tea 30.00
Sandwich 85.50
Cake 120.00
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Total 235.50In text = "the cat sat on the mat with the hat", print how many times "the" appears, the position of the first "at", and whether the text starts with "the".
count(), find() and startswith() are string methods.
text = "the cat sat on the mat with the hat"
print(text.count("the"))
print(text.find("at"))
print(text.startswith("the"))3
5
Truefind() returns -1 when the text is not found, while index() raises a ValueError. Use find() when "not found" is a normal case.