Pycharmでmatplotlibが使えない

前提・実現したいこと

Pythonを学習し始めたばかりの初心者です。
matplotlibをインポートしたはずなのに使えません。

発生している問題・エラーメッセージ

error
1Traceback (most recent call last):
2  File "<input>", line 1, in <module>
3  File "D:\Program Files\JetBrains\PyCharm 2021.2\plugins\python\helpers\pydev\_pydev_bundle\pydev_umd.py", line 198, in runfile
4    pydev_imports.execfile(filename, global_vars, local_vars)  # execute the script
5  File "D:\Program Files\JetBrains\PyCharm 2021.2\plugins\python\helpers\pydev\_pydev_imps\_pydev_execfile.py", line 18, in execfile
6    exec(compile(contents+"\n", file, 'exec'), glob, loc)
7  File "C:/Users/zhang/PycharmProjects/pythonProject1/aaa.py", line 1, in <module>
8    import matplotlib.pyplot as plt
9  File "D:\Program Files\JetBrains\PyCharm 2021.2\plugins\python\helpers\pydev\_pydev_bundle\pydev_import_hook.py", line 21, in do_import
10    module = self._system_import(name, *args, **kwargs)
11  File "C:\Users\zhang\AppData\Local\Programs\Python\Python39\lib\site-packages\matplotlib\pyplot.py", line 36, in <module>
12    import matplotlib.colorbar
13  File "D:\Program Files\JetBrains\PyCharm 2021.2\plugins\python\helpers\pydev\_pydev_bundle\pydev_import_hook.py", line 21, in do_import
14    module = self._system_import(name, *args, **kwargs)
15  File "C:\Users\zhang\AppData\Local\Programs\Python\Python39\lib\site-packages\matplotlib\colorbar.py", line 44, in <module>
16    import matplotlib.contour as contour
17  File "D:\Program Files\JetBrains\PyCharm 2021.2\plugins\python\helpers\pydev\_pydev_bundle\pydev_import_hook.py", line 21, in do_import
18    module = self._system_import(name, *args, **kwargs)
19  File "C:\Users\zhang\AppData\Local\Programs\Python\Python39\lib\site-packages\matplotlib\contour.py", line 17, in <module>
20    import matplotlib.text as text
21  File "D:\Program Files\JetBrains\PyCharm 2021.2\plugins\python\helpers\pydev\_pydev_bundle\pydev_import_hook.py", line 21, in do_import
22    module = self._system_import(name, *args, **kwargs)
23  File "C:\Users\zhang\AppData\Local\Programs\Python\Python39\lib\site-packages\matplotlib\text.py", line 16, in <module>
24    from .textpath import TextPath  # Unused, but imported by others.
25  File "D:\Program Files\JetBrains\PyCharm 2021.2\plugins\python\helpers\pydev\_pydev_bundle\pydev_import_hook.py", line 21, in do_import
26    module = self._system_import(name, *args, **kwargs)
27  File "C:\Users\zhang\AppData\Local\Programs\Python\Python39\lib\site-packages\matplotlib\textpath.py", line 11, in <module>
28    from matplotlib.mathtext import MathTextParser
29  File "D:\Program Files\JetBrains\PyCharm 2021.2\plugins\python\helpers\pydev\_pydev_bundle\pydev_import_hook.py", line 21, in do_import
30    module = self._system_import(name, *args, **kwargs)
31  File "C:\Users\zhang\AppData\Local\Programs\Python\Python39\lib\site-packages\matplotlib\mathtext.py", line 27, in <module>
32    from PIL import Image
33  File "D:\Program Files\JetBrains\PyCharm 2021.2\plugins\python\helpers\pydev\_pydev_bundle\pydev_import_hook.py", line 21, in do_import
34    module = self._system_import(name, *args, **kwargs)
35ModuleNotFoundError: No module named 'PIL'
36

というエラーが出ました以下がソースコードです

該当のソースコード

python
1import matplotlib.pyplot as plt
2import numpy as np
3a=[1228.3,1600.38,653.8,760.07,1500.16,1896.18]
4month = np.arange(1,7)
5plt.rcParams['font.sans-serif']=['SimHei']
6plt.rcParams['axes.unicode_minus']=False
7plt.rcParams["font.size"] = 15
8plt.plot(month,a,"r:D")
9plt.title("title",fontsize = 25, color = 'red')
10plt.xlabel("x")
11plt.ylabel("y")
12plt.show()
13