SyntaxError：语法无效为什么会发生这种错误？

Question

I want to plot 2 graphes at one time. I wrote codes in Jupiter notebook like

import matplotlib.pyplot as plt
import numpy as np
import pandas as pd
import plotly
import plotly.graph_objs as go

import plotly.offline as offline
plotly.offline.init_notebook_mode(connected=False)

x = "test.csv"
df = pd.read_csv(x)

a = df["A"].values.tolist()
b = df["B"].values.tolist()

a = pd.Series(a)
b = pd.Series(b)

data = [
        plotly.graph_objs.Scatter(y = a, mode = 'lines', name = 'A')
        plotly.graph_objs.Scatter(y = b, mode = 'lines', name = 'B', yaxis="y2")
]

layout = plotly.graph_objs.Layout(
    title="A&B",
    xaxis={"title":"Date"},
    yaxis={"title":"Data-a"},
    yaxis2={"title":"Data-b", "overlaying":"y", "side":"right"},
)

fig = plotly.graph_objs.Figure(data=data, layout=layout)
plotly.offline.iplot(fig)

When I run it, I get this error:

plotly.graph_objs.Scatter(y = b, mode = 'lines', name = ‘B’, yaxis="y2")
         ^
SyntaxError: invalid syntax

I think no syntax error in the codes, so I really cannot understand why such an error happens. What is wrong in my codes?How should I fix this?

Answer 1

You're missing commas at the end of these lines:

data = [
        plotly.graph_objs.Scatter(y = a, mode = 'lines', name = 'A'),
        plotly.graph_objs.Scatter(y = b, mode = 'lines', name = 'B', yaxis="y2"),
]