更新2021

正如@eega所提到的，我不再维护这个软件包了。我建议你看看boto3-stubs。它是boto3_type_annotations的一个更成熟的版本。

原始答案

我做了一个可以帮助解决这个问题的软件包，boto3_type_annotations。它可以带文档也可以不带文档。下面是示例用法。在我的github上还有一个使用PyCharm的GIF。

import boto3
from boto3_type_annotations.s3 import Client, ServiceResource
from boto3_type_annotations.s3.waiter import BucketExists
from boto3_type_annotations.s3.paginator import ListObjectsV2

# With type annotations

client: Client = boto3.client('s3')
client.create_bucket(Bucket='foo')  # Not only does your IDE knows the name of this method, 
                                    # it knows the type of the `Bucket` argument too!
                                    # It also, knows that `Bucket` is required, but `ACL` isn't!

# Waiters and paginators and defined also...

waiter: BucketExists = client.get_waiter('bucket_exists')
waiter.wait('foo')

paginator: ListObjectsV2 = client.get_paginator('list_objects_v2')
response = paginator.paginate(Bucket='foo')

# Along with service resources.

resource: ServiceResource = boto3.resource('s3')
bucket = resource.Bucket('bar')
bucket.create()

# With type comments

client = boto3.client('s3')  # type: Client
response = client.get_object(Bucket='foo', Key='bar')

# In docstrings

class Foo:
    def __init__(self, client):
        """
        :param client: It's an S3 Client and the IDE is gonna know what it is!
        :type client: Client
        """
        self.client = client

    def bar(self):
        """
        :rtype: Client
        """
        self.client.delete_object(Bucket='foo', Key='bar')
        return self.client

Allie Fitter提到的boto3_type_annotations已被弃用，但他链接到一个替代方案：https://pypi.org/project/boto3-stubs/

看看aws-samples中的这个项目，它是一个带有boto_stubs的瘦集成层，并且它具有开箱即用的显式类型提示https://github.com/aws-samples/boto-session-manager-project/tree/main