Matplotlib-堆积的条形图，底部

Question

I'm struggling to understand why my stacked bar graph in matplotlib isn't behaving correctly. It has to do with the 'bottom' argument in my plt.bar() function

If I hard code the values I want to plot, everything works correctly:

import matplotlib.pyplot as plt

var1 = 'Bar1' 
var2 = .2403 
var3 = .1256
var4 = .1158

plt.bar(var1, var2, color='green')
plt.bar(var1, var3, bottom=var2, color='blue')
plt.bar(var1, var4, bottom=(var2+var3), color='red')

Here is the correct output and what it should look like:

In my code I have a function that generates some values that are in a list and I will iteratively plot these. Here is what the values look like after doing some math. There is only 1 item in each list:

var1 = 'Bar1'
var2 = [.2403]
var3 = [.1256]
var4 = [.1158]

And now I try to use the same code to plot these:

plt.bar(var1, var2, color='green')
plt.bar(var1, var3, bottom=var2, color='blue')
plt.bar(var1, var4, bottom=(var2+var3), color='red')

But the result does not look right. I am not sure what is happening here:

Answer 1

thanks to the comment above I have a solution:

for i in range(0, len(var1)):
    plt.bar(var1, var2, color='green')
    plt.bar(var1, var3, bottom=var2[i], color='blue')
    plt.bar(var1, var4, bottom=(var2[i]+var3[i]), color='red')