Ben Chuanlong Du's Blog

It is never too late to learn.

ModuleNotFoundError: No Module Named _Ctypes in Python

Things on this page are fragmentary and immature notes/thoughts of the author. Please read with your own judgement!

Issue

The error message "ModuleNotFoundError: No Module Named _Ctypes" is thrown when using Python.

Cause

A crucial built-in module, _ctypes, is either missing from your Python installation or cannot be located …

Rust Error "error: expected item, found 'let'"

Things on this page are fragmentary and immature notes/thoughts of the author. Please read with your own judgement!

The error message "error: expected item, found 'let'" is commonly encountered in Rust when you mistakenly place a let statement in an invalid location. A let statement can only be used …

Spark Issue: IllegalArgumentException: Wrong FS

Things on this page are fragmentary and immature notes/thoughts of the author. Please read with your own judgement!

Symptoms

java.lang.IllegalArgumentException: Wrong FS: hdfs://..., expected: viewfs://...

Possible Causes

The Spark cluster has migrated to Router-based Federation (RBF) namenodes, and viewfs:// (instead of hdfs://) is required to access HDFS …

Spark Issue: ViewFs: Cannot Initialize: Empty Mount Table in Config

Things on this page are fragmentary and immature notes/thoughts of the author. Please read with your own judgement!

Symptoms

java.io.IOException: ViewFs: Cannot initialize: Empty Mount table in config for viewfs://cluster-name-ns02/

Possible Causes

As the error message says, viewfs://cluster-name-ns02 is not configured.

  1. It is possible that …

Spark Issue: ArrowTypeError: Expect a Type but Got a Different Type

Things on this page are fragmentary and immature notes/thoughts of the author. Please read with your own judgement!

Symptom

pyarrow.lib.ArrowTypeError: Expected a string or bytes dtype, got int64

Possible Causes

A pandas_udf tag specifies a return type of String but the corresponding pandas udf returns a different …