Python cannot edit word document - python-3.8

Question

my goal is to replace some text within an existing word docx. However, I have experienced error while using ReplaceAll function. Could you please help to explain the issue? thank you!
my code:
import win32com.client
constants=win32com.client.constants
wordapp=win32com.client.gencache.EnsureDispatch('Word.Application')
worddoc=wordapp.Documents.Open(templatefile)
wordapp.Visible=False
wordapp.Selection.Find.ClearFormatting
wordapp.Selection.Find.Replacement.ClearFormatting
worddoc.Range(0,0).Select()
selection = wordapp.Selection
selection.Find.ClearFormatting()
selection.Find.Replacement.ClearFormatting()
selection.Find.Forward=True
for dummy in myDict.keys():
selection.Find.Text = dummy
selection.Find.Replacement.Text = myDict[dummy]
selection.Find.Execute(Replace=constants.wdReplaceAll)
worddoc.SaveAs(savefile)
worddoc.Close()
wordapp.Application.Quit()
error message:
Traceback (most recent call last):
File "short_py3_1.py", line 75, in <module>
selection.Find.Execute(Replace=constants.wdReplaceAll)
File "C:\Temp\gen_py\3.8\00020905-0000-0000-C000-000000000046x0x8x7\Find.py", line 45, in Execute
return self._oleobj_.InvokeTypes(444, LCID, 1, (11, 0), ((16396, 17), (16396, 17), (16396, 17), (16396, 17), (16396, 17), (16396, 17), (16396, 17), (16396, 17), (16396, 17), (16396, 17), (16396, 17), (16396, 17), (16396, 17), (16396, 17), (16396, 17)),FindText
pywintypes.com_error: (-2147352567, 'Exception occurred.', (0, 'Microsoft Word', 'This command is not available.', 'wdmain11.chm', 37373, -2146823683), None)
my conda package:
ca-certificates 2021.1.19 h9f7ea03_0
certifi 2020.12.5 py38h9f7ea03_0
openssl 1.1.1i hc431981_0
pip 20.3.3 py38h9f7ea03_0
pysimplegui 4.34.0 pypi_0 pypi
python 3.8.5 h5fd99cc_1
pywin32 227 py38he774522_1
setuptools 51.3.3 py38h9f7ea03_4
sqlite 3.33.0 h2a8f88b_0
vc 14.2 h21ff451_1
vs2015_runtime 14.27.29016 h5e58377_2
wheel 0.36.2 pyhd3eb1b0_0
wincertstore 0.2 py38_0
zlib 1.2.11 h33f27b4_4

Answer 1

Sorry, I just figured out myself. the issue is when open word 2019, the program has an default view of "read" mode (which prevents the user to modify the document. you can switch the mode at the right bottom corner of word). Then I changed the word default view from read mode to print layout in word option. the script ran without the error.
more information on "How Do You Make Print Layout the Default View Layout in Microsoft Word?"
Link