**Assignment vs Copy:** list1 = list2 → alias, same object. list1 = list2.copy() (or list2[:]) → shallow copy, new list, same element refs. Nested structures shared in shallow copy. **When to Use:** Alias when you want to modify original through both refs. Shallow copy when you...
This easy-level Python/Coding question appears frequently in data engineering interviews at companies like HCL. While less common, it tests deeper understanding that distinguishes strong candidates.
Start by clearly defining the core concept being asked about. Interviewers want to see that you understand the fundamentals before diving into implementation details. Structure your answer with a definition, then explain the practical application with a concise example.
Assignment vs Copy: list1 = list2 → alias, same object. list1 = list2.copy() (or list2[:]) → shallow copy, new list, same element refs. Nested structures shared in shallow copy.
When to Use: Alias when you want to modify original through both refs. Shallow copy when you need independent list but elements can be shared. Deep copy when elements are mutable and must be independent.
a = [1, [2,3]]
b = a; b[0] = 99 # a[0] also 99
c = a.copy(); c[0] = 1 # a[0] still 99; c[1] shared with a[1]
Production: Copy before in-place transform if original must be preserved. For pipelines: pass copies to avoid accidental mutation.
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Analyze My Answer — FreeAccording to DataEngPrep.tech, this is one of the most frequently asked Python/Coding interview questions, reported at 1 company. DataEngPrep.tech maintains a curated database of 1,863+ real data engineering interview questions across 7 categories, verified by industry professionals.