xlsxmetadata

Really lightweight lib for peeking into xlsx column/row size before you try to open the file with something else

setup

pip install xlsxmetadata

reading from file...

from xlsxmetadata.metadata import get_dimensions, get_sheet_names

my_big_file = '/path/to/my/real_big_file.xlsx'

sheet_names = get_sheet_names(my_big_file)
print(sheet_names)

>>> {'test_sheet': 1}

dimensions = get_dimensions('/path/to/my/real_big_workbook.xlsx', 'test_sheet')
print(dimensions['end_column'])

>>> 16834

print(dimensions['end_row'])

>>> 1200000

reading from flask form...

from io import BytesIO
from xlsxmetadata.metadata import get_dimensions, get_sheet_names

my_big_file = request.files.get('my_big_file')

sheet_names = get_sheet_names(BytesIO(my_big_file.read()))
print(sheet_names)

>>> {'test_sheet': 1}

# you will probably have to reset the read-head
my_big_file.seek(0)

dimensions = get_dimensions(BytesIO(my_big_file.read()), 'test_sheet')
print(dimensions['end_column'])

>>> 16834

print(dimensions['end_row'])

>>> 1200000

This information is stored as metadata in the first few bytes of .xlsx files. For some reason no other libraries (xlrd, openpyxl) seem to give the users access to this data directly.