Python Interview Questions
Python's immutable string type -- formatting, splitting, joining, and Unicode handling.
Ans
A Python string is an immutable sequence of Unicode characters. It supports indexing, slicing, searching, formatting, and many useful methods.
Example
pythonname = "Python" print(name[0], name[-1])
Important Point
String operations that appear to modify a string create or return another string.
Ans
String immutability means an existing string object's characters cannot be changed. This gives predictable value semantics and allows strings to be safely shared and hashed.
Example
pythons = "cat" s = s + "s" print(s)
Important Point
Concatenating many strings repeatedly in a loop can create unnecessary intermediate objects; use a list and `join()` for many pieces.
Ans
An f-string is a formatted string literal that evaluates expressions inside {} and produces readable formatted output.
Example
pythonname = "Amit" age = 25 print(f"{name} is {age} years old")
Important Point
Expressions inside f-strings should be kept simple; complex logic belongs outside the formatting expression.
Ans
Both support formatted strings, but f-strings are usually more concise when formatting values already available in the current scope.
Example
pythonname = "Amit" print(f"Hello {name}") print("Hello {}".format(name))
Important Point
Choose the style supported by the project's Python version and coding conventions.
Ans
split() divides a string into a list of substrings using a separator or whitespace rules when no separator is provided.
Example
pythontext = "Java Python SQL" print(text.split())
Important Point
Repeated whitespace is handled conveniently when the separator is omitted.
Ans
join() combines an iterable of strings into one string using the calling string as the separator.
Example
pythonwords = ["Python", "is", "easy"] print(" ".join(words))
Important Point
Every element supplied to join must be a string.
Ans
replace() substitutes occurrences of one substring with another. strip() removes specified characters from the beginning and end of a string, not from the middle.
Example
pythons = " Python " print(s.strip()) print(s.replace("Python", "Java"))
Important Point
`strip("ab")` removes any leading/trailing a or b characters, not the exact substring "ab".
Ans
Python 3 strings represent Unicode text, allowing code to work with characters from many writing systems. Encoding becomes important when converting text to bytes for files or networks.
Example
pythontext = "नमस्ते" data = text.encode("utf-8") print(data.decode("utf-8"))
Important Point
A Unicode string and encoded bytes are different types.