Plotting line with different colors

Question

import pandas as pd
import matplotlib.pyplot as plt
import numpy as np

df1 = pd.DataFrame(np.random.randint(0,15,size=(15, 1)))
df2 = pd.DataFrame(np.random.randint(20,         


        

Answer 1

Just plot only the part of the dataframe which you want in whatever color you like, e.g. df3.iloc[:15,:].plot(color="green").

import pandas as pd
import matplotlib.pyplot as plt
import numpy as np

df1 = pd.DataFrame(np.random.randint(0,15,size=(15, 1)))
df2 = pd.DataFrame(np.random.randint(20,35,size=(10, 1)))


frames = [df1, df2]
result = pd.DataFrame(pd.concat(frames))

df3 = result.cumsum()
df3 = df3.reset_index(drop=False)
print(df3)
ax = df3.iloc[:15,:].plot(y=0, color="crimson")
df3.iloc[15:,:].plot(y=0, color="C0", ax=ax)
plt.show()

Answer 2

What about

#[...]
df3 = result.cumsum()
df3 = df3.reset_index(drop=False)
plt.plot(df3.mask(df3.apply(lambda x: x.index < 15))[0], color='blue')
plt.plot(df3.mask(df3.apply(lambda x: x.index > 15))[0], color='green')
plt.show()
plt.close()# do not forget this to save you from Runtime Error.