可视化仓库运行报错，内置值无效。

问题遇到的现象和发生背景

在python编程从入门到实践这本书中，第十七章，可视化仓库。我按照书上写下来的东西，为什么一直报错说 值无效。没明白

问题相关代码，请勿粘贴截图

import requests

from plotly.graph_objs import Bar
from plotly import offline

# 执行API调用并存储响应。
url='https://api.github.com/search/repositories?q=language:python&sort=stars'
headers={'Accept':'application/vnd.github.v3+json'}
r=requests.get(url,headers=headers)                     
print(f"Status code:{r.status_code}")

# 处理结果。
response_dict=r.json()
repo_dicts= response_dict['items']
repo_names,stars = [],[]
for repo_dict in repo_dicts:
    repo_names.append(repo_dict['name'])
    stars.append(repo_dict['stargazers_count'])

# 可视化。
data = [{
    'type':'bar',
    'x':'repo_names',
    'y':'stars',
}]
my_layout = {
    'title':'Github上最受欢迎的python项目',
    'xaxis':{'title':'Repository'},
    'yaxis':{'title':'Stars'},
}

fig = {'data':data,'layout':my_layout}
offline.plot(fig,filename='python_repos.html')

运行结果及报错内容

ValueError: 
    Invalid value of type 'builtins.str' received for the 'x' property of bar
        Received value: 'repo_names'

    The 'x' property is an array that may be specified as a tuple,
    list, numpy array, or pandas Series
[Finished in 3.8s with exit code 1]
[cmd: ['py', '-u', 'C:\\Users\\a\\Desktop\\数据分析\\python_repos_visual.py']]
[dir: C:\Users\a\Desktop\数据分析]

我的解答思路和尝试过的方法

我想要达到的结果

了解运行报错的原因，得到解决办法。

data = [{
    'type':'bar',
    'x':'repo_names',
    'y':'stars',
}]

改为

data = [{
    'type':'bar',
    'x':repo_names,
    'y':stars,
}]

data = [{
'type': 'bar',
'x': repo_names,
'y': stars,
}]