[BUG] Matplotlib code throwing error for temporal charts

[Innko]

Describe the bug
For Matplotlib temporal charts "from pandas import Timestamp\n" is not added to generated code.
Error: Timestamp is not defined.
To Reproduce
generate matplotlib code for a temporal chart with:
vis.to_code("matplotlib")

import matplotlib.pyplot as plt
plt.rcParams.update(
{
"axes.titlesize": 20,
"axes.titleweight": "bold",
"axes.labelweight": "bold",
"axes.labelsize": 16,
"legend.fontsize": 14,
"legend.title_fontsize": 15,
"xtick.labelsize": 13,
"ytick.labelsize": 13,
}
)
import numpy as np
from math import nan
df = pd.DataFrame({'year': {0: Timestamp('1950-01-01 00:00:00'), 1: Timestamp('1951-01-01 00:00:00'), 2: Timestamp('1952-01-01 00:00:00'), 3: Timestamp('1955-01-01 00:00:00'), 4: Timestamp('1956-01-01 00:00:00'), 5: Timestamp('1957-01-01 00:00:00'), 6: Timestamp('1958-01-01 00:00:00'), 7: Timestamp('1959-01-01 00:00:00'), 8: Timestamp('1960-01-01 00:00:00'), 9: Timestamp('1961-01-01 00:00:00'), 10: Timestamp('1963-01-01 00:00:00'), 11: Timestamp('1964-01-01 00:00:00'), 12: Timestamp('1965-01-01 00:00:00'), 13: Timestamp('1966-01-01 00:00:00'), 14: Timestamp('1967-01-01 00:00:00'), 15: Timestamp('1968-01-01 00:00:00'), 16: Timestamp('1969-01-01 00:00:00'), 17: Timestamp('1970-01-01 00:00:00'), 18: Timestamp('1971-01-01 00:00:00'), 19: Timestamp('1972-01-01 00:00:00'), 20: Timestamp('1973-01-01 00:00:00'), 21: Timestamp('1974-01-01 00:00:00'), 22: Timestamp('1975-01-01 00:00:00'), 23: Timestamp('1976-01-01 00:00:00'), 24: Timestamp('1978-01-01 00:00:00'), 25: Timestamp('1979-01-01 00:00:00'), 26: Timestamp('1980-01-01 00:00:00'), 27: Timestamp('1981-01-01 00:00:00'), 28: Timestamp('1982-01-01 00:00:00'), 29: Timestamp('1983-01-01 00:00:00'), 30: Timestamp('1984-01-01 00:00:00'), 31: Timestamp('1985-01-01 00:00:00'), 32: Timestamp('1986-01-01 00:00:00'), 33: Timestamp('1987-01-01 00:00:00'), 34: Timestamp('1988-01-01 00:00:00'), 35: Timestamp('1989-01-01 00:00:00'), 36: Timestamp('1990-01-01 00:00:00'), 37: Timestamp('1991-01-01 00:00:00'), 38: Timestamp('1993-01-01 00:00:00'), 39: Timestamp('1994-01-01 00:00:00'), 40: Timestamp('1995-01-01 00:00:00'), 41: Timestamp('1997-01-01 00:00:00'), 42: Timestamp('1998-01-01 00:00:00'), 43: Timestamp('1999-01-01 00:00:00'), 44: Timestamp('2000-01-01 00:00:00'), 45: Timestamp('2002-01-01 00:00:00'), 46: Timestamp('2004-01-01 00:00:00'), 47: Timestamp('2005-01-01 00:00:00'), 48: Timestamp('2006-01-01 00:00:00'), 49: Timestamp('2007-01-01 00:00:00'), 50: Timestamp('2009-01-01 00:00:00'), 51: Timestamp('2010-01-01 00:00:00'), 52: Timestamp('2011-01-01 00:00:00'), 53: Timestamp('2012-01-01 00:00:00'), 54: Timestamp('2013-01-01 00:00:00'), 55: Timestamp('2014-01-01 00:00:00'), 56: Timestamp('2015-01-01 00:00:00'), 57: Timestamp('2016-01-01 00:00:00'), 58: Timestamp('2017-01-01 00:00:00'), 59: Timestamp('2018-01-01 00:00:00'), 60: Timestamp('2019-01-01 00:00:00'), 61: Timestamp('2020-01-01 00:00:00')}, 'Record': {0: 3, 1: 1, 2: 1, 3: 1, 4: 1, 5: 1, 6: 2, 7: 1, 8: 1, 9: 2, 10: 3, 11: 1, 12: 2, 13: 1, 14: 1, 15: 2, 16: 3, 17: 4, 18: 1, 19: 1, 20: 2, 21: 4, 22: 2, 23: 1, 24: 3, 25: 7, 26: 2, 27: 2, 28: 2, 29: 2, 30: 1, 31: 3, 32: 3, 33: 3, 34: 3, 35: 4, 36: 1, 37: 1, 38: 4, 39: 2, 40: 4, 41: 5, 42: 4, 43: 2, 44: 3, 45: 2, 46: 2, 47: 4, 48: 1, 49: 3, 50: 2, 51: 3, 52: 2, 53: 2, 54: 3, 55: 3, 56: 2, 57: 2, 58: 6, 59: 6, 60: 11, 61: 9}})
fig, ax = plt.subplots()
x_pts = df['year']
y_pts = df['Record']
ax.plot(x_pts, y_pts)
ax.set_xlabel('year')
ax.set_ylabel('Number of Records')

fig

[dorisjlee]

Thank you for reporting this issue @Innko! I just fixed this issue in the codebase.