Maintaining Formulae when Adding Rows/Columns - python

I'm doing some excel sheet Python automation using openpyxl and I'm having an issue when I try to insert columns or rows into my sheet.
I'm modifying an existing excel sheet which has basic formula in it (i.e. =F2-G2) however when I insert a row or column before these cells, the formula do not adjust accordingly like they would if you would perform that action in excel.
For example, inserting a column before column F should change the formula to =G2-H2 but instead it stays at =F2-G2...
Is there any way to work around this issue? I can't really iterate through all the cells and fix the formula because the file contains many columns with formula in them.

openpyxl is a file format library and not an application like Excel and does not attempt to provide the same functionality. Translating formulae in cells that are moved should be possible with the library's tokeniser but this ignores any formulae that refer to the cells being moved on the same worksheet or in the same workbook.

Easy, just iterate from your inserted row downward to the max row and change formulae's row number accordingly, below code is just a example:
#insert a new row after identified row
ws.insert_rows(InsertedRowNo)
#every time you insert a new row, you need to adjust all formulas row numbers after the new row.
for i in range (InsertedRowNo,ws.max_row):
ws.cell(row=i,column=20).value='=HYPERLINK(VLOOKUP(TRIM(A{0}),dict!$A$2:$B$1001,2,0),A{0})'.format(i)

Related

Write rows bottom in Google Sheet from Python

I am trying to write rows with python in one google sheet. I found function .insert_row() with that new rows are written in the top of my google sheet. How can I write it in the bottom? Any ideas?
That is how I am trying it now:
sheet.insert_rows(df_test.values.tolist())
I believe your goal is as follows.
In your situation, for example, the sheet has 1000 rows. The rows which are not empty are from 1st row to row 10.
You want to put the values from the next empty row that it's row 11. This is the 1st empty row.
From your script of sheet.insert_rows(df_test.values.tolist()), you want to achieve this using gspread for python.
In this case, how about the following modification? In this modification, append_rows method is used instead of insert_rows.
From:
sheet.insert_rows(df_test.values.tolist())
To:
sheet.append_rows(df_test.values.tolist(), value_input_option="USER_ENTERED")
Reference:
append_rows

Cell Format for a range of cells using xlsxwriter

I am using xlsxwriter to export pandas dataframe to excel file. I need format a range of cells without using worksheet.write function as the data is already present in cells.
If I am using set_row or set_column, it is adding the format to entire row or column.
Please help me find a solution.
I need format a range of cells without using worksheet.write function as the data is already present in cells.
In general that isn't possible with XlsxWriter. If you want to specify formatting for cells then you need to do it when you write the data to the cells.
There are some options which may or may not suit your needs:
Row and Column formatting. However that formats the rest of the row or column and not just the cells with data.
Add a table format via add_table().
Add a conditional format via conditional_format().
However, these are just workarounds. If you really need to format the cells then you will need to do it when using write().

Pandas: read rows from an excel file and write them to another one

Hi I'm pretty new to python and I'm trying to use pandas as described in the title.
My problem is very simple but I'm having some trouble with it: I need to read some rows from an excel file and, if the row's first column value it's not equal to the next row's first column value, I have to insert an empty row in the excel.
In order to do this I would like to read a row from my original excel, compare his value with the next one and, if they are the equal, write them in the other excel file. If they are different, I want to write an empty row, and then the different value row.
thanks in advance!

Check the missing value in an excel table

I am working on my assignment of data visualization. Firstly, I have to check dataset I found, and do the data wrangling, if it is necessary. The data consists of several particles index for air quality in Madrid, those data were collected by different stations.
I found some values are missing in the table. How can I check those missing values quickly by tools (python or R or Tableau) and replace those value?
In Python, you can use the pandas module to load the Excel file as a DataFrame. Post this, it is easy to substitute the NaN/missing values.
Let's say your excel is named madrid_air.xlsx
import pandas as pd
df = pd.read_excel('madrid_air.xlsx')
Post this, you will have what they call a DataFrame which consists of the data in the excel file in the same tabular format with column names and index. In the DataFrame the missing values will be loaded as NaN values. So in order to get the rows which contains NaN values,
df_nan = df[df.isna()]
df_nan will have the rows which has NaN values in them.
Now if you want to fill all those NaN values with let's say 0.
df_zerofill = df.fillna(0)
df_zerofill will have the whole DataFrame with all the NaNs substituted with 0.
In order to specifically fill coulmns use the coumn names.
df[['NO','NO_2']] = df[['NO','NO_2']].fillna(0)
This will fill the NO and NO_2 columns' missing values with 0.
To read up more about DataFrame: https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.DataFrame.html
To read up more about handling missing data in DataFrames : https://pandas.pydata.org/pandas-docs/stable/user_guide/missing_data.html
There are several libraries for python to process excel spreadsheets. My favorite one is openpyxl. It transforms the spreadsheets into a dataframe in which you then can address a specific field by it coordinates. Which comes in quite handy is that it also recognizes labels of rows and columns. Of course you can also update your tables
with it. But be careful, if you are using corrupted code your xlsx-files might get permantly damaged
Edit1:
import openpyxl
wb = openpyxl.load_workbook('filename.xlsx')
# if your worksheet is the first one in the workbook
ws = wb.get_sheet_names(wb.get_sheet_by_name()[0])
for row in ws.iter_rows('G{}:I{}'.format(ws.min_row,ws.max_row)):
for cell in row:
if cell.value is None:
cell.value = 0
Well, in Tableau you can creat a worksheet, drag n Drop the lowest level of granurality in the dimension table (Blue pill) in and put the columns (as measures) in the same chart.
If your table is trully atomic, then you will get a response in your worksheet at the bottom right telling you about the null values. Clicking on it allows you to clear or replace these specifics values in the data of the workbook.
Just to clearify, Its not the "hi end" and the Coding way, but is the simplest one.
PS: You can also check for missing values in the data input window of the Tableau by filtering the columns by "null" values.
PS2: If you want to Chang it dynamic, the you Will need to use formulas like:
IF ISNULL(Measure1)
THEN (Measure2) ˜ OR Another Formula
ELSE null
END

xlwings udf function erase next cell on excel

I have a little problem on excel using xlwings and i really don't know how to fix it.
When i'm using an UDF function that return for example a panda dataframe, let suppose that my dataframe is 3 colums width (no necessary condition on rows), then on the 4th columns in excel, if i write some datas on it, my panda dataframe will erase it as soon as i calculate the sheet... Although the dataframe is not using this column at all while it's 3 columns large and not 4 ...
I don't know if i'm clear enough. Let me know !
thank you very much in advance.
#xw.func
#xw.ret(expand='table')
def hello(nb):
nb = int(nb)
return [["hello","you"] for i in range(nb)]
before recalculate the sheet
after recalculate the sheet
It seems that in the documentation of xlwings, it is necessary to have an empty row and column at the bottom and to the right. if not it will overwrite it
http://docs.xlwings.org/en/stable/api.html#xlwings.xlwings.ret

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