DocumentLoaderError
langchain.document_loaders.base.DocumentLoaderError
Stack trace
langchain.document_loaders.base.DocumentLoaderError: File not found: /path/to/nonexistent/file.txt
File "/usr/local/lib/python3.9/site-packages/langchain/document_loaders/base.py", line 45, in load
raise DocumentLoaderError(f"File not found: {file_path}") Why it happens
This error happens because the DocumentLoader attempts to read a file from a path that does not exist or is inaccessible due to permissions or incorrect path specification. The loader expects a valid file path to load documents, and missing files cause this exception.
Detection
Check file existence and permissions before calling the loader. Use os.path.exists() or try/except DocumentLoaderError to catch missing file issues early.
Causes & fixes
The file path provided to the DocumentLoader is incorrect or misspelled.
Verify and correct the file path string to point to the exact existing file location.
The file has been moved, deleted, or is not present in the expected directory.
Ensure the file exists at the specified location or update the path to the current file location.
Insufficient permissions prevent the loader from accessing the file.
Check and update file system permissions to allow read access for the running process.
Code: broken vs fixed
from langchain.document_loaders import TextLoader
loader = TextLoader('/path/to/nonexistent/file.txt')
docs = loader.load() # This line raises DocumentLoaderErrorimport os
from langchain.document_loaders import TextLoader
file_path = os.environ.get('DOC_PATH', '/path/to/existing/file.txt')
if not os.path.exists(file_path):
raise FileNotFoundError(f"File not found: {file_path}")
loader = TextLoader(file_path)
docs = loader.load()
print(f"Loaded {len(docs)} documents successfully.") # Fixed: checks path before loadingWorkaround
Wrap the load call in try/except DocumentLoaderError and provide a fallback path or notify the user to supply a valid file path.
Prevention
Implement file path validation and existence checks in your application logic before initializing DocumentLoaders to avoid runtime file not found errors.