为什么我只传入一个关键字参数错误时会得到多个值？

Question

我用以下函数调用函数load（）：

load(r'M:\test_3.p', marker = '*', linestyle = '-.', color = 'b', grid = True)

在该函数中，我正在打印kwargs [＆＃39; color＆＃39;]并且我只得到一个值，我得到值b（我最初在函数调用中输入的值）。我还有其他原因会收到此错误吗？在脚本的最末端的exec（plotting_string）行中出现错误。有人可以帮忙吗？

错误具体是：

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "functions_mar.py", line 236, in load
    exec(plotting_string)
  File "<string>", line 1, in <module>
TypeError: plot() got multiple values for keyword argument 'color' 

以下代码：

def load(string, **kwargs):   
    #Unpickling the data in order
    f = open(string, 'r')
    raw_data = pk.load(f)
    title = pk.load(f) 
    xlabel = pk.load(f) 
    ylabel = pk.load(f)
    line_labels = pk.load(f)
    line_colors = pk.load(f)
    line_marker = pk.load(f)
    f.close()    


    #Specifying the graph  
    fig0 = plt.figure()
    ax = fig0.add_subplot(1,1,1)
    plt.ion()    

    # Handles plt. methods (included some basic ones but in future will add library of all)
    if kwargs.get('title') is not None:
        plt.title(kwargs['title'])
        del kwargs['title']
    else:
        plt.title(title)
    if kwargs.get('xlabel') is not None:
        plt.xlabel(kwargs['xlabel'])
        del kwargs['xlabel']
    else: 
        plt.xlabel(xlabel)
    if kwargs.get('ylabel') is not None:
        plt.ylabel(kwargs['ylabel'])
        del kwargs['ylabel']
    else: 
        plt.ylabel(ylabel)
    if kwargs.get('grid') is not None:
        try:        
            plt.grid(kwargs['grid'])
            del kwargs['grid']
        except Exception as e:
            plt.grid(True)
            del kwargs['grid']
            print 'Error: ',e, '\n ERROR: Grid can only be BOOLEAN: True or False.'                      
    else: 
        plt.grid(True)    


    #VARIABLE ARGUMENT HANDLER     
    # Handles variable keyword arguments as to not coincide with the defaults  
    if kwargs is not None: 
           plotting_string  ='ax.plot(x,y, label = line_labels[i], color = line_colors[i], marker = line_marker, **kwargs)' 
           if kwargs.get('marker') is not None:
                   plotting_string = plotting_string.replace('line_marker', '\''+ kwargs['marker'] +'\'' )
                   del kwargs['marker']

           if kwargs.get('color') is not None:
                   if len(kwargs['color']) != len(raw_data): 
                       if len(kwargs['color']) == 1:
                           try:

                               plotting_string = plotting_string.replace('line_colors[i]', '\'' + kwargs['color']+'\'' )
                           except: 
                               print 'Color must be a string!!'
                       else:
                           print 'Must enter as many colors as there are lines'
                           del kwargs['color']  

                   else: 
                       colors  = kwargs['color'] 
                       plotting_string = plotting_string.replace('line_colors', 'colors')
                       del kwargs['color']


    #Regenerating the plot from the unpickled data     
    print kwargs['color']
    for i,line in enumerate(raw_data): 
       x = line[0]
       y = line[1]

       if kwargs is not None: 
           exec(plotting_string)
       else: # User didnt enter any additional arguments 
           ax.plot(x,y, label = line_labels[i], color = line_colors[i], marker = line_marker, **kwargs)




    plt.legend()
    plt.show()