Traceback (most recent call last):
File "/Users/.../PycharmProjects/Sequence4/Fit.py", line 18, in <module>
plot_url = py.plot(data, filename='basic-error-bar')
File "/Users/.../anaconda/lib/python3.5/site-packages/plotly/plotly/plotly.py", line 241, in plot
res = _send_to_plotly(figure, **plot_options)
File "/Users.../anaconda/lib/python3.5/site-packages/plotly/plotly/plotly.py", line 1401, in _send_to_plotly
validate_credentials(credentials)
File "/Users/.../anaconda/lib/python3.5/site-packages/plotly/plotly/plotly.py", line 1350, in validate_credentials
raise exceptions.PlotlyLocalCredentialsError()
plotly.exceptions.PlotlyLocalCredentialsError:
Couldn't find a 'username', 'api-key' pair for you on your local machine. To sign in temporarily (until you stop running Python), run:
import plotly.plotly as py
py.sign_in('username', 'api_key')

Even better, save your credentials permanently using the 'tools' module:
import plotly.tools as tls
tls.set_credentials_file(username='username', api_key='api-key')

For more help, see https://plot.ly/python.