无法解包非可迭代AxesSubplot对象 - Matplotlib

Question

我正在编写一个Python函数，可以创建两个平行的图表，并共用它们的2个轴:

def PlotManager(data1,data2,fig):
    f, (ax1, ax2) = fig.subplots(2, 1, sharey=True,sharex=True)

    #Plot1 sopra
    x_axis = data1.index
    #Plot and shade the area between the upperband and the lower band grey
    ax1.fill_between(x_axis,data1['Upper'],data1['Lower'], color = 'grey', alpha= 0.5)
    #Plot the closing price and the moving average
    ax1.plot(x_axis,data1['Close'],color = 'gold',lw = 3,label = 'Close Price', alpha= 0.5)
    ax1.plot(x_axis,data1['SMA'],color = 'blue',lw = 3,label = 'Simple Moving Average', alpha= 0.5)
    ax1.scatter(x_axis,data1['Buy'],color="green", lw=3,label="Buy",marker = "^", alpha=1)
    ax1.scatter(x_axis,data1['Sell'],color="red", lw=3,label="Sell",marker = "v", alpha = 1)
    #Set the title and show the image
    ax1.set_title("Bollinger Band for Amazon")
    plt.xticks(rotation = 45)

    #Plot 2 Sotto
    ax2.set_title('RSI_Plot')
    ax2.plot(x_axis,data2['RSI'])
    ax2.axhline(0,linestyle='--',alpha=0.5, color="grey")
    ax2.axhline(10,linestyle='--',alpha=0.5, color="orange")
    ax2.axhline(20,linestyle='--',alpha=0.5, color="green")
    ax2.axhline(30,linestyle='--',alpha=0.5, color="red")
    ax2.axhline(70,linestyle='--',alpha=0.5, color="red")
    ax2.axhline(80,linestyle='--',alpha=0.5, color="green")
    ax2.axhline(90,linestyle='--',alpha=0.5, color="orange")
    ax2.axhline(100,linestyle='--',alpha=0.5, color="grey")

但是却给我返回一个 cannot unpack non-iterable AxesSubplot object 错误：

[Command: python -u C:\Users\Nicolò\Documents\Git\ProgettoTradingBot\ProgettoTradeBot\GUIprova2.py]
C:\Users\Nicolò\Documents\Git\ProgettoTradingBot\ProgettoTradeBot\BollingerBandsFinal.py:63: MatplotlibDeprecationWarning: Adding an axes using the same arguments as a previous axes currently reuses the earlier instance.  In a future version, a new instance will always be created and returned.  Meanwhile, this warning can be suppressed, and the future behavior ensured, by passing a unique label to each axes instance.
  ax = f.add_subplot(111)
C:\Users\Nicolò\Documents\Git\ProgettoTradingBot\ProgettoTradeBot\BollingerBandsFinal.py:63: MatplotlibDeprecationWarning: Adding an axes using the same arguments as a previous axes currently reuses the earlier instance.  In a future version, a new instance will always be created and returned.  Meanwhile, this warning can be suppressed, and the future behavior ensured, by passing a unique label to each axes instance.
  ax = f.add_subplot(111)
Traceback (most recent call last):
  File "C:\Users\Nicolò\AppData\Local\Programs\Python\Python38\lib\site-packages\matplotlib\cbook\__init__.py", line 196, in process
    func(*args, **kwargs)
  File "C:\Users\Nicolò\AppData\Local\Programs\Python\Python38\lib\site-packages\matplotlib\animation.py", line 951, in _start
    self._init_draw()
  File "C:\Users\Nicolò\AppData\Local\Programs\Python\Python38\lib\site-packages\matplotlib\animation.py", line 1743, in _init_draw
    self._draw_frame(next(self.new_frame_seq()))
  File "C:\Users\Nicolò\AppData\Local\Programs\Python\Python38\lib\site-packages\matplotlib\animation.py", line 1766, in _draw_frame
    self._drawn_artists = self._func(framedata, *self._args)
  File "C:\Users\Nicolò\Documents\Git\ProgettoTradingBot\ProgettoTradeBot\GUIprova2.py", line 48, in animate
    PlotManager(BollingerBands(df,f),RSI(df,f2),f)
  File "C:\Users\Nicolò\Documents\Git\ProgettoTradingBot\ProgettoTradeBot\mostraGrafici.py", line 7, in PlotManager
    f, (ax1, ax2) = fig.subplots(2, 1, sharey=True,sharex=True)
TypeError: cannot unpack non-iterable AxesSubplot object

我该如何处理这个错误？

- Nicolò Raccichini

Answer 1

plt.subplots(2, 1, ...)的返回值是一个元组figure, array(subplot0, subplot1)，因此您可以正确地将其拆包为一个图形和两个子图。 相反，fig.subplots(2, 1, ...)的返回值是subplot0, subplot1（因为您已经有了图形...）当您尝试拆包它时，它等效于：

f = subplot0
ax0, ax1 = subplot1

这导致出现错误：TypeError: 无法解包非可迭代的AxesSubplot对象

---

由于您没有使用下面标记为f的对象，因此应该编写：

ax1, ax2 = fig.subplots(2, 1, sharey=True,sharex=True)

- gboffi