Fetch a Remote Text File and Compute Mean, Median and Mode of Employee Counts

In a coding interview without AI assistance, you are asked to write a Python program that fetches data from a remote plain-text file and computes the median, the average (arithmetic mean) and the mode of the employee counts it contains. The report does not describe the file's layout, so agree on it with the interviewer before parsing; a natural starting assumption is one record per line with the employee count as one of its fields. The interviewer followed the exercise with Python-specific questions. ```hint Decide the bad-line policy first Before writing any statistics, decide what the program does with a line whose employee count is blank, non-numeric or negative, and how it reports what it skipped. ``` ```hint Ties and even lengths Work out by hand what the median of four numbers is, and what the mode is when two different counts appear equally often. ``` ### Clarifying Questions - What is the file's exact layout: a single number per line, or delimited records with a header row, and which field holds the employee count? - Are employee counts always whole numbers, and what should happen to blank, malformed or missing values: skip them, count them, or fail? - When several counts tie for the most frequent, should the mode be all of them, the smallest, or the first one seen? - For an even number of values, is the median the mean of the two middle values? - How large can the file be: does it fit in memory, or must it be processed as a stream? - Is only the standard library allowed, or may you use packages such as requests? - What should the program do if the download fails or the file contains no valid counts? ### What a Strong Answer Covers - Fetching with a timeout, a check of the HTTP status, correct text decoding, and a clear error for a failed download or an empty file - Parsing that follows the agreed layout and applies an explicit, reported policy to malformed or missing counts - Correct mean, median (including the even-length case) and mode with an agreed tie rule, and no failure on a single value - Small functions for fetching, parsing and computing, tested without the network - Command of the relevant Python tools and their edge-case behavior ### Follow-up Questions - The file is several gigabytes. Which of the three statistics can you compute in one pass with little memory, and what do you do about the median? - How does `statistics.mode` behave when two values tie, and how does `statistics.multimode` differ? - How would you test the fetching and parsing code without calling the real URL? - The server is slow and sometimes returns errors. How do you make the download robust without retrying forever?