Sebastian Witowski • 12/1/2022

dict() vs. {}

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This article analyzes the performance difference between using dict() and {} to create dictionaries in Python. Through benchmarks in Python 3.11 and 3.8, it demonstrates that the literal syntax {} is 2-4 times faster. It explains the bytecode-level reason using the dis module: {} uses BUILD_MAP directly, while dict() requires a function lookup and call. It also notes dict() is still necessary for creating dictionaries from iterables.

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#Python #performance #benchmarking
dict() vs. {}

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