# Respect User-Specified User-Agent in WebBaseLoader
This pull request modifies the `WebBaseLoader` class initializer from
the `langchain.document_loaders.web_base` module to preserve any
User-Agent specified by the user in the `header_template` parameter.
Previously, even if a User-Agent was specified in `header_template`, it
would always be overridden by a random User-Agent generated by the
`fake_useragent` library.
With this change, if a User-Agent is specified in `header_template`, it
will be used. Only in the case where no User-Agent is specified will a
random User-Agent be generated and used. This provides additional
flexibility when using the `WebBaseLoader` class, allowing users to
specify their own User-Agent if they have a specific need or preference,
while still providing a reasonable default for cases where no User-Agent
is specified.
This change has no impact on existing users who do not specify a
User-Agent, as the behavior in this case remains the same. However, for
users who do specify a User-Agent, their choice will now be respected
and used for all subsequent requests made using the `WebBaseLoader`
class.
Fixes#4167
## Before submitting
============================= test session starts
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collecting ... collected 1 item
test_web_base.py::TestWebBaseLoader::test_respect_user_specified_user_agent
============================== 1 passed in 3.64s
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PASSED [100%]
## Who can review?
Community members can review the PR once tests pass. Tag
maintainers/contributors who might be interested: @eyurtsev
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Co-authored-by: Eugene Yurtsev <eyurtsev@gmail.com>
