Stream Large Log Files | Dataford Interview Questions

Problem

Given a list of log lines lines, where each line is a JSON object with string fields "user" and "event", return a dictionary mapping each user to the number of distinct event types seen for that user. Invalid JSON lines or lines missing either field should be ignored. The solution should process the input in a memory-efficient way and avoid storing parsed records unnecessarily.

Constraints

1 <= len(lines) <= 10^5
Each line length is at most 10^4
user and event values, when present, are non-empty strings
Invalid JSON lines may appear anywhere in the input

Problem

Constraints

1 <= len(lines) <= 10^5
Each line length is at most 10^4
user and event values, when present, are non-empty strings
Invalid JSON lines may appear anywhere in the input

Problem

Constraints

1 <= len(lines) <= 10^5
Each line length is at most 10^4
user and event values, when present, are non-empty strings
Invalid JSON lines may appear anywhere in the input

Problem

Constraints

1 <= len(lines) <= 10^5
Each line length is at most 10^4
user and event values, when present, are non-empty strings
Invalid JSON lines may appear anywhere in the input