Line plot doesn't show when used with a datetime variable on the x-axis

Question

I'm trying to plot a bar graph that is accompanied by two line graphs. The barplot shows fine but I can't seem to get the lines plotted above the barplot. Here's the code:

fig, ax = plt.subplots(figsize=(18,9))
sns.set_style("darkgrid")
g=sns.barplot(date_new, df["Net xG (xG - Opponent's xG)"].astype("float"), palette="coolwarm_r", hue=df["Net xG (xG - Opponent's xG)"].replace({"-":0}).astype("float"), dodge=False, data=df)
plt.plot(date_new, -df["Opponent's xG"].astype("float"), color="gold", marker="o")
plt.plot(date_new, df["xG (Expected goals)"].astype("float"), color="indianred", marker="o")
g.set_xticklabels(stuff[::-1], rotation=90)
g.get_legend().remove()
g.set(xlim=([-0.8, 46]))
plt.show()

date_new variable used for the x-axis is in datetime64[ns] format. A weird thing I noticed is that if I reformat date_new as a string like date_new.astype("str"), the line plots show but the order is reversed.

I tried to "re-reverse" the order of which dates are sorted by by changing the x-axis variable to date_new[::-1], but that doesn't seem to change the line plots' order.

Here's a screenshot of how the x (Date) and y (xG) axis variables look on the dataframe:

Answer 1

You are trying to combine a bar graph with two line plots. It seems you are having issues matching your x-axis variables. As @Henry Ecker said above, the x axis labels on a bar plot are cosmetic and do not represent an actual date time axis. Consequently, the x-axis values for your bar plot are simply the numbers 0 to 46.

To fix your problem, simply make the line plot x values a list from 0 to 46.

I simulated your data and demonstrate the solution in the example below.

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

# create data 
# there are 46 rows each representing a game against some other club
# colums include: date of game, opposing club, club goals, opposing club goals
# goal range is 0-5

df = pd.DataFrame({
    'date':pd.date_range(start='1/2021', end='7/1/2021', periods=46),
    'club':['Team: ' + str(n) for n in range(1,47)],
    'goals': np.random.randint(0, 5, 46),
    'opposing_goals':np.random.randint(0, 5, 46)
})

df['net_goals'] = df.goals - df.opposing_goals

fig, ax = plt.subplots(figsize=(18,9)) 
sns.set_style("darkgrid")              

g=sns.barplot(
    x=df.date, y=df.net_goals, 
    palette="coolwarm_r", hue=df.net_goals, dodge=False, data=df
    )

plt.plot(np.arange(0,46), -df.opposing_goals, color="gold", marker="o") 
plt.plot(np.arange(0,46), df.goals, color="indianred", marker="o")

g.set_xticklabels(df.club, rotation=45)
g.get_legend().remove()
g.set(xlim=([-0.8, 46]))