Hide legend entries in a plotly figure

You can set any parameters of figure before plotting like here:

import pandas as pd
import plotly.offline as py
import plotly.graph_objs as go
import cufflinks as cf
cf.go_offline()

df = pd.DataFrame(data=[[0, 1, 2], [3, 4, 5]], columns=['A', 'B', 'C'])

# get figure property
fig = df.iplot(kind='scatter', asFigure=True)

# set showlegend property by name of trace
for trace in fig['data']: 
    if(trace['name'] != 'B'): trace['showlegend'] = False

# generate webpage
py.plot(fig)

Not sure if this is a recent addition, but in current versions of plotly (4.0 and above), you can do fig.update(layout_showlegend=False).