问题
I would like to simulate the Excel autofit function in Python's xlsxwriter. According to this url, it is not directly supported: http://xlsxwriter.readthedocs.io/worksheet.html
However, it should be quite straightforward to loop through each cell on the sheet and determine the maximum size for the column and just use worksheet.set_column(row, col, width) to set the width.
The complications that is keeping me from just writing this are:
- That URL does not specify what the units are for the third argument to set_column.
- I can not find a way to measure the width of the item that I want to insert into the cell.
- xlsxwriter does not appear to have a method to read back a particular cell. This means I need to keep track of each cell width as I write the cell. It would be better if I could just loop through all the cells, that way a generic routine could be written.
回答1:
As a general rule, you want the width of the columns a bit larger than the size of the longest string in the column. The with of 1 unit of the xlsxwriter columns is about equal to the width of one character. So, you can simulate autofit by setting each column to the max number of characters in that column.
Per example, I tend to use the code below when working with pandas dataframes and xlsxwriter.
It first finds the maximum width of the index, which is always the left column for a pandas to excel rendered dataframe. Then, it returns the maximum of all values and the column name for each of the remaining columns moving left to right.
It shouldn't be too difficult to adapt this code for whatever data you are using.
def get_col_widths(dataframe):
# First we find the maximum length of the index column
idx_max = max([len(str(s)) for s in dataframe.index.values] + [len(str(dataframe.index.name))])
# Then, we concatenate this to the max of the lengths of column name and its values for each column, left to right
return [idx_max] + [max([len(str(s)) for s in dataframe[col].values] + [len(col)]) for col in dataframe.columns]
for i, width in enumerate(get_col_widths(dataframe)):
worksheet.set_column(i, i, width)
回答2:
I agree with Cole Diamond. I needed to do something very similar, it worked fine for me. where self.columns is my list of columns
def set_column_width(self):
length_list = [len(x) for x in self.columns]
for i, width in enumerate(length_list):
self.worksheet.set_column(i, i, width)
回答3:
I recently ran into this same issue and this is what I came up with:
r = 0
c = 0
for x in list:
worksheet.set_column('{0}:{0}'.format(chr(c + ord('A'))), len(str(x)) + 2)
worksheet.write(r, c, x)
c += 1
In my example r would be the row number you are outputting to, c would be the column number you are outputting to (both 0 indexed), and x would be the value from list that you are wanting to be in the cell.
the '{0}:{0}'.format(chr(c + ord('A'))) piece takes the column number provided and converts it to the column letter accepted by xlsxwriter, so if c = 0 set_column would see 'A:A', if c = 1 then it would see 'B:B', and so on.
the len(str(x)) + 2 piece determines the length of the string you are trying to output then adds 2 to it to ensure that the excel cell is wide enough as the length of the string does not exactly correlate to the width of the cell. You may want to play with rather you add 2 or possibly more depending on your data.
The units that xlsxwriter accepts is a little harder to explain. When you are in excel and you hover over where you can change the column width you will see Width: 8.43 (64 pixels). In this example the unit it accepts is the 8.43, which I think is centimeters? But excel does not even provide a unit, at least not explicitly.
Note: I have only tried this answer on excel files that contain 1 row of data. If you will have multiple rows, you will need to have a way to determine which row will have the 'longest' information and only apply this to that row. But if each column will be roughly the same size regardless of row, then this should work fine for you.
Good luck and I hope this helps!
回答4:
There is another workaround to simulate Autofit that I've found on the Github site of xlsxwriter. I've modified it to return the approximate size of horizontal text (column width) or 90° rotated text (row height):
from PIL import ImageFont
def get_cell_size(value, font_name, font_size, dimension="width"):
""" value: cell content
font_name: The name of the font in the target cell
font_size: The size of the font in the target cell """
font = ImageFont.truetype(font_name, size=font_size)
(size, h) = font.getsize(str(value))
if dimension == "height":
return size * 0.92 # fit value experimentally determined
return size * 0.13 # fit value experimentally determined
This doesn't address bold text or other format elements that might affect the text size. Otherwise it works pretty well.
To find the width for your columns for autofit:
def get_col_width(data, font_name, font_size, min_width=1):
""" Assume 'data' to be an iterable (rows) of iterables (columns / cells)
Also, every cell is assumed to have the same font and font size.
Returns a list with the autofit-width per column """
colwidth = [min_width for col in data[0]]
for x, row in enumerate(data):
for y, value in enumerate(row):
colwidth[y] = max(colwidth[y], get_cell_size(value, font_name, font_size))
return colwidth
回答5:
Cole Diamond's answer is awesome. I just updated the subroutine to handle multiindex rows and columns.
def get_col_widths(dataframe):
# First we find the maximum length of the index columns
idx_max = [max([len(str(s)) for s in dataframe.index.get_level_values(idx)] + [len(str(idx))]) for idx in dataframe.index.names]
# Then, we concatenate this to the max of the lengths of column name and its values for each column, left to right
return idx_max + [max([len(str(s)) for s in dataframe[col].values] + \
[len(str(x)) for x in col] if dataframe.columns.nlevels > 1 else [len(str(col))]) for col in dataframe.columns]
回答6:
Here is a version of code that supports MultiIndex for row and column - it is not pretty but works for me. It expands on @cole-diamond answer:
def _xls_make_columns_wide_enough(dataframe, worksheet, padding=1.1, index=True):
def get_col_widths(dataframe, padding, index):
max_width_idx = []
if index and isinstance(dataframe.index, pd.MultiIndex):
# Index name lengths
max_width_idx = [len(v) for v in dataframe.index.names]
# Index value lengths
for column, content in enumerate(dataframe.index.levels):
max_width_idx[column] = max(max_width_idx[column],
max([len(str(v)) for v in content.values]))
elif index:
max_width_idx = [
max([len(str(s))
for s in dataframe.index.values] + [len(str(dataframe.index.name))])
]
if isinstance(dataframe.columns, pd.MultiIndex):
# Take care of columns - headers first.
max_width_column = [0] * len(dataframe.columns.get_level_values(0))
for level in range(len(dataframe.columns.levels)):
values = dataframe.columns.get_level_values(level).values
max_width_column = [
max(v1, len(str(v2))) for v1, v2 in zip(max_width_column, values)
]
# Now content.
for idx, col in enumerate(dataframe.columns):
max_width_column[idx] = max(max_width_column[idx],
max([len(str(v)) for v in dataframe[col].values]))
else:
max_width_column = [
max([len(str(s)) for s in dataframe[col].values] + [len(col)])
for col in dataframe.columns
]
return [round(v * padding) for v in max_width_idx + max_width_column]
for i, width in enumerate(get_col_widths(dataframe, padding, index)):
worksheet.set_column(i, i, width)
回答7:
My version that will go over the one worksheet and autoset the field lengths:
from typing import Optional
from xlsxwriter.worksheet import (
Worksheet, cell_number_tuple, cell_string_tuple)
def get_column_width(worksheet: Worksheet, column: int) -> Optional[int]:
"""Get the max column width in a `Worksheet` column."""
strings = getattr(worksheet, '_ts_all_strings', None)
if strings is None:
strings = worksheet._ts_all_strings = sorted(
worksheet.str_table.string_table,
key=worksheet.str_table.string_table.__getitem__)
lengths = set()
for row_id, colums_dict in worksheet.table.items(): # type: int, dict
data = colums_dict.get(column)
if not data:
continue
if type(data) is cell_string_tuple:
iter_length = len(strings[data.string])
if not iter_length:
continue
lengths.add(iter_length)
continue
if type(data) is cell_number_tuple:
iter_length = len(str(data.number))
if not iter_length:
continue
lengths.add(iter_length)
if not lengths:
return None
return max(lengths)
def set_column_autowidth(worksheet: Worksheet, column: int):
"""
Set the width automatically on a column in the `Worksheet`.
!!! Make sure you run this function AFTER having all cells filled in
the worksheet!
"""
maxwidth = get_column_width(worksheet=worksheet, column=column)
if maxwidth is None:
return
worksheet.set_column(first_col=column, last_col=column, width=maxwidth)
just call set_column_autowidth with the column.
来源：https://stackoverflow.com/questions/29463274/simulate-autofit-column-in-xslxwriter