问题 I am reading a csv file with German date format. Seems like it worked ok in this post: Picking dates from an imported CSV with pandas/python However, it seems like in my case the date is not recognized as such. I could not find any wrong string in the test file. import pandas as pd import numpy as np %matplotlib inline import matplotlib.pyplot as plt from matplotlib import style from pandas import DataFrame style.use('ggplot') df = pd.read_csv('testdata.csv', dayfirst=True, parse_dates=True)