On 2019-06-26 13:15, Cecil Westerhof wrote:
Cecil Westerhof <ce...@decebal.nl> writes:
I was asked to copy a certain line from about 300 Excel lines to a new
Excel file. That is not something I would like to do by hand and I
immediately thought: that should be possible with Python.
And it is. I was surprised how fast I could write that with openpyxl.
My first try was not very neat, but a proof of concept. Then by
looking better at the possibilities I could get much cleaner code. But
I am still not completely happy. At the moment I have the following
code:
wb_out = Workbook()
for filepath in filepathArr:
current_row = []
wb_in = load_workbook(filepath)
for cell in wb_in.active[src_row]:
current_row.append(cell.value)
wb_out.active.append(current_row)
wb_in.close()
wb_out.save(report_start + datetime.now().strftime('%Y-%m-%d') + report_end)
wb_out.close()
I could not find a way to copy a row from one workbook to another.
That is why I put the row in current_row and do an append. Am I
overlooking something, or is that really the way to do this?
I am not used to writing GUI programs. (I have to learn tkinter also.)
What is the best way to handle potential errors? It could go wrong on
line 1, 4, 5, 7, 8, 9 and 10. Should I catch every exception alone, or
all together, or something in between?
I rewrote it like:
wb_in = None
wb_out = None
try:
wb_out = Workbook()
for filepath in filepathArr:
current_row = []
wb_in = load_workbook(filepath)
for cell in wb_in.active[src_row]:
current_row.append(cell.value)
wb_out.active.append(current_row)
wb_in.close()
wb_out.save(report_start + datetime.now().strftime('%Y-%m-%d') +
report_end)
wb_out.close()
messagebox.showinfo(info_str, created_report)
except Exception as err:
if wb_in:
wb_in.close()
if wb_out:
Missing ():
wb_close
messagebox.showerror(error_str,
error_generate + '\n\n\n\n' + str(err))
Is it necessary to close the workbooks to circumvent a resource leak?
Is it a problem when a workbook is closed two times? If so I need to
make sure that this is not possible.
Does Workbook support the 'with' statement?
If it does, then that's the best way of doing it.
(Untested)
with Workbook() as wb_out:
for filepath in filepathArr:
current_row = []
with load_workbook(filepath) as wb_in:
for cell in wb_in.active[src_row]:
current_row.append(cell.value)
wb_out.active.append(current_row)
wb_out.save(report_start + datetime.now().strftime('%Y-%m-%d')
+ report_end)
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