Where the Lines Break

An easy Python interview practice problem on DataDriven. Write the Python and run it against test cases, with instant feedback.

Domain
Python
Difficulty
easy
Seniority
L3

Problem

Access-log lines arrive with ragged whitespace: fields run together under uneven spacing and stray leading or trailing gaps. Break each line into its whitespace-separated fields, keeping only the real tokens, and hand back an empty list when a line holds nothing but whitespace.

Every record hides its fields behind noise. Pull the real ones loose.

Example 1

Input:

line = "GET /home 200"

Output:

["GET","/home","200"]

Example 2

Input:

line = "  POST   /login   503  "

Output:

["POST","/login","503"]

Worked solution and explanation

What this really is

Underneath the log-parsing costume, this is a one-liner whose entire difficulty is one fork: .split() versus .split(' '). The bare call collapses every run of whitespace and silently drops the empty gaps, so padded and ragged lines come out clean. Pass a literal space and Python preserves every empty string sitting between your double spaces. Reach for .split(' ') on a line like ' POST /login ' and you hand back a list studded with '' tokens that no downstream parser asked for. It also will not split a tab- or newline-delimited line at all.

How to get there

Step 1: Split on whitespace runs

Call .split() with no arguments on line. The argument-less form treats any maximal run of whitespace (spaces, tabs, newlines) as a single delimiter, so inconsistent padding stops mattering.

Step 2: Let the default drop the empties

There is no second step. The no-argument split also discards leading, trailing, and interior empty fields, so the non-empty tokens are exactly what you return. An all-whitespace line falls out as an empty list for free.

The solution

Default split with automatic whitespace handling
def tokenize(line: str) -> list:
    return line.split()

No arguments means runs of whitespace collapse and empty tokens vanish.

`line.split(' ')`
On ' POST /login ' returns ['', '', 'POST', '', '', '/login', '', '']. You now own the empty-token cleanup, and tabs and newlines are not separators.
`line.split()`
On the same input returns ['POST', '/login']. Whitespace runs collapse, edges trim, empties drop, and tabs and newlines are handled too.

Common follow-up questions