cannot import name 'HTTPException' from 'urllib3.connection' - aws-lambda

Question

I am building an application on AWS Lambda using serverless framework.
And trying to import requests library through requirements.txt.
But, it didn't work. came out "cannot import name 'HTTPException' from 'urllib3.connection'" error message.
I can't understand why it doesn't work.
please help.
serverless.yml
service: test-app
plugins:
- serverless-offline
- serverless-package-external
- serverless-python-requirements
custom:
stage: ${opt:stage, self:provider.stage}
pythonRequirements:
dockerizePip: false
slim: true
provider:
name: aws
runtime: python3.7
stage: dv
region: ap-northeast-2
timeout: 10
memorySize: 128
stackName: ${self:service}
variableSyntax: "\\${((?!AWS)[ ~:a-zA-Z0-9._'\",\\-\\/\\(\\)]+?)}"
profile: test-profile
role: arn:aws:iam::1234:role/role-test
environment:
domainPrefix: 'kic'
moduleName: 'deptest2'
phasePrefix: ${self:custom.stage}
projectPrefix: ‘han’
regionPrefix: 'an2'
apiName: api-an2-dv-${self:service}
vpc:
securityGroupIds:
- sg-001
subnetIds:
- subnet-001
- subnet-002
functions:
dep2:
handler: dep2_handler.dep2_handler
name: lmd-an2-dv-${self:service}-deptest2
requirements.txt
-i https://pypi.python.org/simple
requests==2.22.0
dep2_handler.py
import requests
def dep2_handler(event, context):
try:
print(event)
except Exception:
print('fail to handle event data: {}'.format(event))
return

Answer 1

I think the error message was a bit misleading.
As per my comment, there was an offending line in requirements.txt:
The line -i https://pypi.python.org/simple needed to be removed.