PANDAS: Execute to_excel successfully,but no output file - python

When I use to_excel to generate excel file, no error occurred , but no output file available. can't find anything,any file in my supposed location...
And I don't know why..
import pandas as pd
import os
import xlrd
import openpyxl
pd.set_option('display.width',None)
DIR = 'E:\Process'
datapath =os.path.join(DIR, 'Data.xlsx')
formatpath = os.path.join(DIR, 'Format.xlsx')
df = pd.read_excel(datapath)
df1=pd.read_excel(formatpath)
for i in range(0, len(df)):
target = (df.iloc[i,17])
df2 = df1
df2.iat[3,3] = target
print(df2)
filename = df.iloc[i,2]
filename = str(filename) + ".xlsx"
sourcepath = os.path.join(DIR, filename)
writer = pd.ExcelWriter(sourcepath)
df2.to_excel(writer)
print(sourcepath)

Expanding on the comment:
Use writer.save() after calling to_excel.
Alternatively you can use the with statement as suggested in the docs: https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.ExcelWriter.html

When I'm trying to re-run this code on my local machine, I'm running into an error with setting DIR to 'E:\Process' because of the escaping of "\" for windows machines. Have you tried "E:\\Process"? or try it as a raw string literal r'E:\Process'?

Related

How to read a csvfile on FTP that is compressed on a zip/folder

I'm trying to :
read a .csv file (compressed in a zipfile that is stored on FTP) by using ftplib
store the .csv file on a virtual file on memory by using io
transform the virutal file to a dataframe by using pandas
For that I'm using the code below and it works really fine for the first scenario (path1, see image above) :
CODE :
import ftplib
import zipfile
import io
import pandas as pd
ftp = ftplib.FTP("theserver_name")
ftp.login("my_username","my_password")
ftp.encoding = "utf-8"
ftp.cwd('folder1/folder2')
filename = 'zipFile1.zip'
download_file = io.BytesIO()
ftp.retrbinary("RETR " + filename, download_file.write)
download_file.seek(0)
zfile = zipfile.ZipFile(download_file)
df = pd.read_csv(zfile.namelist()[0], delimiter=';')
display(df)
But in the second scenario (path2) and after changing my code, I get the error below :
CODE UPDATE :
ftp.cwd('folder1/folder2/')
filename = 'zipFile2.zip'
ERROR AFTER UPDATE :
FileNotFoundError: [Errno 2] No such file or directory:
'folder3/csvFile2.csv'
It seems like Python don't recognize the folder3 (contained in the zipFile2). Is there any explanation for that, please ? How can we fix that ? I tried with ftp.cwd('folder3') right before pd.read.csv() but it doesn't work..
Thanks to Serge Ballesta in his post here, I finally figure out how to transform csvFile2.csv to a DataFrame :
import ftplib
import zipfile
import io
import pandas as pd
ftp = ftplib.FTP("theserver_name")
ftp.login("my_username","my_password")
ftp.encoding = "utf-8"
flo = io.BytesIO()
ftp.retrbinary('RETR /folder1/folder2/zipFile2.zip', flo.write)
flo.seek(0)
with zipfile.ZipFile(flo) as archive:
with archive.open('folder3/csvFile2.csv') as fd:
df = pd.read_csv(fd, delimiter=';')
display(df)

Python pathlib not accepted by Pandas.ExcelWriter(..)

After finally getting Pandas to output my file as a spreadsheet (silly issue), I ran into an issue with the file path input not being read properly, even as a raw string. Eventually I stumbled upon the pathlib library, and it's been successful in allowing me to read and write to my file as needed. However, now I'm back to ExcelWriter complaining about my file again.
Here's my ugly attempt at using pathlib to create the paths (directories substituted):
import pandas as pd
core = input("Core number ('core_#k'): ")
part = input("Part name ('part_#'): ")
file_level = 'core_' + core + 'k'
in_file_name = file_level + '_part_' + part + '.txt'
out = in_file_name[:-4] + '.ods'
# format filenames
path_raw = Path("DRIVELABEL:\someDirectories\\")
raw_text_path = Path(path_raw) / "raw_text" / file_level / in_file_name
spreadsheet_path = Path(path_raw) / "spreadsheets" / file_level / out
Error:
FileNotFoundError: [Errno 2] No such file or directory: 'DRIVELABEL:/SomeDirectories/outputFile.ods'
I can't figure out how to get ExcelWriter to write this file properly. The only thing I can think right now is that the file_level for spreadsheet_path doesn't exist yet, but shouldn't it be created at write?
with pd.ExcelWriter(spreadsheet_path.as_posix(), engine='odf') as doc:
df.to_excel(doc, sheet_name="Sheet1", index=False)

Pandas, Python - Problem with converting xlsx to csv

I found to have problem with conversion of .xlsx file to .csv using pandas library.
Here is the code:
import pandas as pd
# If pandas is not installed: pip install pandas
class Program:
def __init__(self):
# file = input("Insert file name (without extension): ")
file = "Daty"
self.namexlsx = "D:\\" + file + ".xlsx"
self.namecsv = "D:\\" + file + ".csv"
Program.export(self.namexlsx, self.namecsv)
def export(namexlsx, namecsv):
try:
read_file = pd.read_excel(namexlsx, sheet_name='Sheet1', index_col=0)
read_file.to_csv(namecsv, index=False, sep=',')
print("Conversion to .csv file has been successful.")
except FileNotFoundError:
print("File not found, check file name again.")
print("Conversion to .csv file has failed.")
Program()
After running the code the console shows the ValueError: File is not a recognized excel file error
File i have in that directory is "Daty.xlsx". Tried couple of thigns like looking up to documentation and other examples around internet but most had similar code.
Edit&Update
What i intend afterwards is use the created csv file for conversion to .db file. So in the end the line of import will go .xlsx -> .csv -> .db. The idea of such program came as a training, but i cant get past point described above.
You can use like this-
import pandas as pd
data_xls = pd.read_excel('excelfile.xlsx', 'Sheet1', index_col=None)
data_xls.to_csv('csvfile.csv', encoding='utf-8', index=False)
I checked the xlsx itself, and apparently for some reason it was corrupted with columns in initial file being merged into one column. After opening and correcting the cells in the file everything runs smoothly.
Thank you for your time and apologise for inconvenience.

Combining excel workbook sheet into one using python

I have roughly 30 excel workbooks I need to combine into one. Each workbook has a variable number of sheets but the sheet I need to combine from each workbook is called "Output" and the format of the columns in this sheet is consistent.
I need to import the Output sheet from the first file, then append the remaining files and ignore the header row.
I have tried to do this using glob/pandas to no avail.
You could use openpyxl. Here's a sketch of the code:
from openpyxl import load_workbook
compiled_wb = load_workbook(filename = 'yourfile1.xlsx')
compiled_ws = compiled['Output']
for i in range(1, 30):
wb = load_workbook(filename = 'yourfile{}.xlsx'.format(i))
ws = wb['Output']
compiled_ws.append(ws.rows()[1:]) # ignore row 0
compiled_wb.save('compiled.xlsx')
Method shown by Clinton c. Brownley in Foundations for Analytics with Python:
execute in shell indicating the path to the folder with excel files ( make sure the argument defining all_workbooks is correct) and then followed by the excel output file as follows:
python script.py <the /path/ to/ excel folder/> < your/ final/output.xlsx>
script.py:
import pandas as pd
import sys
import os
import glob
input_path = sys.argv[1]
output_file = sys.argv[2]
all_workbooks = glob.glob(os.path.join(input_file, '*.xlsx'))
all_df = []
for workbook in all_workbooks:
all_worksheets = pd.read_excel(workbook, sheetname='Output', index_col=None)
for worksheet, data in all_worksheets.items:
all_df.append(data)
data_concatenated = pd.concat(all_df, axis=0, ignore_index=True)
writer = pd.ExcelWriter(output_file)
data_concatenated.to_excel(writer, sheetname='concatenated_Output', index=False)
writer.save()
This will probably get down-voted because this isn't a Python answer, but honestly, I wouldn't use Python for this kind of task. I think you are far better off installing the AddIn below, and using that for the job.
https://www.rondebruin.nl/win/addins/rdbmerge.htm
Click 'Merge all files from the folder in the Files location selection' and click 'Use a Worksheet name' = 'Output', and finally, I think you want 'First cell'. Good luck!

pd.read_excel throws PermissionError if file is open in Excel

Whenever I have the file open in Excel and run the code, I get the following error which is surprising because I thought read_excel should be a read only operation and would not require the file to be unlocked?
Traceback (most recent call last):
File "C:\Users\Public\a.py", line 53, in <module>
main()
File "C:\Users\Public\workspace\a.py", line 47, in main
blend = plStream(rootDir);
File "C:\Users\Public\workspace\a.py", line 20, in plStream
df = pd.read_excel(fPath, sheetname="linear strategy", index_col="date", parse_dates=True)
File "C:\Users\Public\Continuum\Anaconda35\lib\site-packages\pandas\io\excel.py", line 163, in read_excel
io = ExcelFile(io, engine=engine)
File "C:\Users\Public\Continuum\Anaconda35\lib\site-packages\pandas\io\excel.py", line 206, in __init__
self.book = xlrd.open_workbook(io)
File "C:\Users\Public\Continuum\Anaconda35\lib\site-packages\xlrd\__init__.py", line 394, in open_workbook
f = open(filename, "rb")
PermissionError: [Errno 13] Permission denied: '<Path to File>'
Generally Excel have a lot of restrictions when opening files (can't open the same file twice, can't open 2 different files with the same name ..etc).
I don't have excel on machine to test, but checking the docs for read_excel I've noticed that it allows you to set the engine.
from the stack trace you posted it seems like the error is thrown by xlrd which is the default engine used by pandas.
try using any of the other ones
Supported engines: “xlrd”, “openpyxl”, “odf”, “pyxlsb”, default “xlrd”.
so try with the rest, like
df = pd.read_excel(fPath, sheetname="linear strategy", index_col="date", parse_dates=True, engine="openpyxl")
I know this is not a real answer, but you might want to submit a bug report to pandas or xlrd teams.
As a workaround I suggest making python create a copy of the original file then read from the copy. After that the code should delete the copied file. It's a bit of extra work but should work.
Example
import shutil
shutil.copy("C://Test//Test.xlsx", "C://Test//koko.xlsx")
I would suggest using the xlwings module instead which allows for greater functionality.
Firstly, you will need to load your workbook using the following line:
If the spreadsheet is in the same folder as your python script:
import xlwings as xw
workbook = xw.Book('myfile.xls')
Alternatively:
workbook = xw.Book('"C:\Users\...\myfile.xls')
Then, you can create your Pandas DataFrame, by specifying the sheet within your spreadsheet and the cell where your dataset begins:
df = workbook.sheets[0].range('A1').options(pd.DataFrame,
header=1,
index=False,
expand='table').value
When specifying a sheet you can either specify a sheet by its name or by its location (i.e. first, second etc.) in the following way:
workbook.sheets[0] or workbook.sheets['sheet_name']
Lastly, you can simply install the xlwings module by using Pip install xlwings
Mostly there is no issues in your code. [ If you publish the code it will be easier.]
You need to change the permissions of the directory you are using so that all users have read and write permissions.
I got this to work by first setting the working directory, then opening the file. Maybe something to do with shared drive permissions and read_excel function.
import os
import pandas as pd
os.chdir("c:\\Users\\...\\")
filepath = "...\\filename.xlsx"
sheetname = 'sheet1'
df_xls = pd.read_excel(filepath, sheet_name=sheetname, engine='openpyxl')
I fix this error simply closing the .xlsx file that was open.
You can set engine = 'xlrd', then you can run the code while Excel has the file open.
df = pd.read_excel(filename, sheetname, engine = 'xlrd')
You may need to pip install xlrd if you don't have it
You may also want to check if the file has a password? Alternatively you can open the file with the password required using the code below:
import sys
import win32com.client
xlApp = win32com.client.Dispatch("Excel.Application")
print "Excel library version:", xlApp.Version
filename, password = <-- enter your own filename and password
xlwb = xlApp.Workbooks.Open(filename, Password=password)
# xlwb = xlApp.Workbooks.Open(filename)
xlws = xlwb.Sheets([insert number here]) # counts from 1, not from 0
print xlws.Name
print xlws.Cells(1, 1) # that's A1
You can set engine='python' then you can run it even if the file is open
df = pd.read_excel(filename, engine = 'python')

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