Python script that reads a file and plots its records.

plot-response-performance.py

import matplotlib.pyplot as plt

def read_file():
    with open("response-times-records.txt") as f:
        # This assumes that lines are formatted like so:
        # 42.123456|2021-07-01 12:00:00.000000
        return [line.rstrip().split("|") for line in f]

def plot_response_times():
    records = read_file()
    x = [e[1] for e in records]
    y = [float(e[0]) for e in records]

    plt.scatter(x, y)
    plt.ylabel("Response Time")
    plt.xlabel("Timestamp")
    plt.show()

plot_response_times()