matplotlib 数据点绘制但它们之间没有线？

Question

I want to plot a line chart with multiple data sets on the same axes, so the markers show up but not the line. I really can't see what I am doing wrong. Can someone put another set of eyes on this, please?

Here is the data print:

looking at 2015-08-05 83.0 AA attribs sector= Materials shape= o kolor= b x = 2015-08-05 y =  83.0
looking at 2015-08-06 50.0 AA attribs sector= Materials shape= o kolor= b x = 2015-08-06 y =  50.0
looking at 2015-08-07 42.0 AA attribs sector= Materials shape= o kolor= b x = 2015-08-07 y =  42.0
looking at 2015-08-10 75.0 AA attribs sector= Materials shape= o kolor= b x = 2015-08-10 y =  75.0

Here is the code segment:

for count, symb in enumerate(my_symbols):
   sector = sector_format[str(sym_sect[symb])][0]
   shape = sector_format[str(sym_sect[symb])][1]
   kolor = sector_format[str(sym_sect[symb])][2]
   x = my_dates[count]
   y = rank_2010[count]
   print("looking at",x,y,symb,"attribs",
         "sector=",sector,
         "shape=",shape,
         "kolor=",kolor,
         "x =",x,
         "y = ",y)

  if symb == 'AA' or symb == "AAPL":
     plt.plot(x,y,lw=5,color=kolor,linestyle='solid',marker=shape)

plt.title('hv 20 to 10 ranks')
plt.xlabel('dates')
plt.ylabel('symbol ranks')
plt.show()

Answer 1

Your problem is that you are calling plot multiple times wanting it to collect the data you give it into one set. That's not how plot works. You need to form a data set (one "line" in your plot) and pass that to plot . Something along the lines of:

x_list = []
y_list = []

for count, symb in enumerate(my_symbols):
   sector = sector_format[str(sym_sect[symb])][0]
   shape = sector_format[str(sym_sect[symb])][1]
   kolor = sector_format[str(sym_sect[symb])][2]
   x = my_dates[count]
   y = rank_2010[count]
   print("looking at",x,y,symb,"attribs",
         "sector=",sector,
         "shape=",shape,
         "kolor=",kolor,
         "x =",x,
         "y = ",y)

  if symb == 'AA' or symb == "AAPL":
      x_list.append(x)
      y_list.append(y)

plt.plot(x_list,y_list,lw=5,color=kolor,linestyle='solid',marker=shape)

plt.title('hv 20 to 10 ranks')
plt.xlabel('dates')
plt.ylabel('symbol ranks')
plt.show()

This may not be exactly what you want. I'm unclear on what you're trying to do with different colors and marks, so you may have to modify it. However, I think it should get you in the right direction at least.