使用pyp时的数据处理

Question

我遇到了这样一个问题：如果用户第一次想要绘制图形，它可以正常工作，但如果再次选择相同的选项，我会看到如下错误。在我看来，pyplot持有的一些资源似乎没有得到释放。我的理解正确吗？如果正确，如何纠正？如果错了，可能的原因是什么

只要多一点信息——只有在我尝试绘制图表时才会发生——如果我只想显示数据，它就可以正常工作

代码：

default_options = {'0' : 'Below are the options',
                   '1' : '1 . Enter File path\'s for processing',
                   '2' : '2 . Display all categories',
                   '3' : '3 . Display type of forms',
                   '4' : '4 . Display for given form annual result',
                   '5' : '5 . Compare two form annual result ',
                   '6' : '6 . Compare two years annual result',
                   '99': '0 . Type 0 to exit '
                   }

labels = ["1st_quat", "2nd_quat", "3rd_quat", "4th_quat"]

def plotBarGraph(self, fiscal_year):
    index = np.arange(len(labels))
    bar_width = 0.1
    fig, ax = plt.subplots()
    appli_received = [data[0] for data in fiscal_year]
    appli_accepted = [data[1] for data in fiscal_year]
    appli_denied = [data[2] for data in fiscal_year]
    appli_pending = [data[3] for data in fiscal_year]

    plt.bar(index, appli_received, bar_width, alpha = 0.5, color='b')
    plt.bar(index + bar_width, appli_accepted,bar_width, alpha = 0.5, color='r')
    plt.bar(index + bar_width * 2, appli_denied, bar_width, alpha = 0.5, color='g')
    plt.bar(index + bar_width * 3,  appli_pending,bar_width, alpha = 0.5, color='k')
    plt.xticks(index, labels, rotation = 35)
    ax.tick_params(axis='both', which='major')
    plt.legend(['Received', 'Approved', 'Denied', 'Pending'], loc='upper left')
    plt.show()

def getUserInput(self):
    self.displayUserOption()
    user_input = int(raw_input())
    if self.validateUserInput(user_input):
        if user_input:
            self.processForAllFile(user_input)
            self.getUserInput()
    else:
        print " Please enter valid option \n "
        self.getUserInput() 

当用户再次尝试打印图形时打印错误（在选择再次打印之前，我也手动关闭打印）

self.plotBarGraph(report)

    plt.bar(index, appli_received, bar_width, alpha = 0.5, color='b')
  File "/usr/lib/pymodules/python2.7/matplotlib/pyplot.py", line 2089, in bar
    ret = ax.bar(left, height, width, bottom, **kwargs)
  File "/usr/lib/pymodules/python2.7/matplotlib/axes.py", line 4733, in bar
    nbars)
AssertionError: incompatible sizes: argument 'height' must be length 4 or scalar

Answer 1

看起来labels变量（看起来是全局变量）和plotBarGraph中fiscal_year的维度之间可能不匹配。变量index的维数取决于labels的长度。然后将fiscal_year展平为未知维度的列表，并尝试将它们用作具有len(labels)条的条形图的高度

当len(labels) != len(fiscal_year)时，有太多或太少的高度matplotlib无法正确绘制条形图，这就是您看到错误的原因