Develop Reference

Python convert.txt to .csv without having a specific file name

I am currently working on an application that will convert a messy text file full of data into an organized CSV. It currently works well but when I convert the text file to csv I want to be able to select a text file with any name. The way my code is currently written, I have to name the file "file.txt". How do I go about this?
Here is my code. I can send the whole script if necessary. Just to note this is a function that is linked to a tkinter button. Thanks in advance.
def convert():
df = pd.read_csv("file.txt",delimiter=';')
df.to_csv('Cognex_Data.csv')

Try defining your function as follow:
def convert(input_filename, output_filename='Cognex_Data.csv'):
df = pd.read_csv(input_filename, delimiter=';')
df.to_csv(output_filename)
And for instance use it as follow:
filename = input("Enter filename: ")
convert(filename, "Cognex_Data.csv")
You can also put "Cognex_Data.csv" as a default value for the output_filename argument in the convert function definition (as done above).
And finally you can use any way you like to get the filename (for instance tkinter.filedialog as suggested by matszwecja).

I haven't worked with tkinter, but PySimplyGUI, which to my knowledge is built on tkinter so you should have the possibility to extract the variables that correspond to the name of the file selected by the user. That's what I'm doing using PySimpleGUIon a similar problem.
Then, extract the file name selected by the user through the prompt and pass it as an argument to your function:
def convert(file):
df = pd.read_csv("{}.txt".format(file), delimiter=';')
df.to_csv('Cognex_Data.csv')

How to read a lot of excel files in python pandas?

I have lots of excel files(xlsx format) and want to read and handle them.
For example, file names are ex201901, ex201902, .... 201912.
Its name is made by exYYYYMM format.
Anyway, to import these files in pandas as an usual case, it's easy.
import pandas as pd
df201901 = pd.read_excel(r'C:\\users\ex201901.xlsx)
df201902 = pd.read_excel(r'C:\\users\ex201902.xlsx)
df201903 = pd.read_excel(r'C:\\users\ex201903.xlsx)
df201904 = pd.read_excel(r'C:\\users\ex201904.xlsx)
....
df201912 = pd.read_excel(r'C:\\users\ex201912.xlsx)
However, it seem to be a boring and tedius.
In SAS program, I use Macro() syntax. But in python, I have no idea how to handle.
Can you help me how to handle the multiple and repeated jobs in easy way, like a SAS MACRO().
Thanks for reading.

Given that you'll probably want to somehow work with all data frames at once afterwards, it's a smell if you even put them into separate local variables, and in general, whenever you're experiencing a "this task feels repetitive because I'm doing the same thing over and over again", that calls for introducing loops of some sort. As you're planning to use pandas, chances are that you'll be iterating soon again (now that you have your files, you're probably going to be performing some transformations on the rows of those files), in which case you'll probably be best off looking into how control flow a la loops works in Python (and indeed in pandas) in general; good tutorials are plentiful.
In your particular case, depending on what kind of processing you are planning on doing afterwards, you'd probably benefit from having something like
df2019 = [pd.read_excel(rf'C:\users\ex2019{str(i).zfill(2)}.xlsx') for i in range(1, 13)]
With that, you can access the individual data frames through e.g. df2019[5] to get the data frame corresponding to June, or you can collapse all of them into a single data frame using df = pd.concat(df2019) if that's what suits your need.
If you have less structure in your file names, glob can come in handy. With that, the above could become something like
import glob
df2019 = list(map(pd.read_excel, glob.glob(r'C:\users\ex2019*.xlsx')))

You can use OS module from python. It has a method listdir which stores all the file names in the folder. Check the code below:
import os, re
listDir = os.listdir(FILE_PATH)
dfList = []
for aFile in listDir:
if re.search(r'ex20190[0-9]{1}.xlsx', aFile):
tmpDf = pd.read_excel(FILE_PATH + aFile)
dfList.append(tmpDf)
outDf = pd.concat(dfList)

How to extract all variable and their value from a python script with location like "C:\\Users\\SomeFolder\\PythonFile.py"?

I am working on a text editor made with python and i want to add a feature of Variable Explorer in my editor I am not able to extract the variable values from a python file. My basic working principle is that my program takes location of the current edited file and try to import it but I am not able to import because that is string not an object. It is bit confusing so let me show the code.
fileName='C:\Users\Project.py'
class varExplorer:
def ShowVarList(editfile):
editfile.replace('\','.')
editfile.replace('.py','')
editfile.replace(':','')
# so the file path will be like C.Users.Project
import editfile # the problem
print(editfile.__dict__)# here i will get dictionary of values
varExplorer.ShowVarList(fileName)
help taken for dict
print(editfile.__dict__)
from
I want to extract all the variable names with a python script, from a python file, without editing the python file
The main problem is that it cannot import from a string
import editfile # the problem
because it is a string and import does not take strings
So I want a function which can print all the variable and their values from a specific python file from any location.

Use importlib
import importlib
importlib.import_module(editfile)
Also be careful, str is immutable in Python, replace returns a new string and does not modify its argument.
So you get:
import importlib
class VarExplorer:
def show_var_list(editfile):
editfile = editfile.replace('\\','.')
editfile = editfile.replace('.py','')
editfile = editfile.replace(':','')
# so the file path will be like C.Users.Project
module = importlib.import_module(editfile) # the solution
print(vars(module))

Python 3 use a code from a file

I have two Python files. In my main file I work with a openpyxl module. In my second file I have many string lines with concatenating using Excel file cells, for example:
'/ip address=' + sheet['D'+ row].value + '\n'
and many others. But there is a problem, if I import that file to a main file using:
from file2 import *
I get many errors about undefined names like:
NameError: name 'sheet' is not defined
And it is really defined only in my main file, like:
wb = openpyxl.load_workbook(filename='clients.xlsx')
sheet = wb.get_sheet_by_name('Page1')
How can I import everything from my file2 and get it work?

As far as I can wrap my head around it, import only imports functions. execfile(*path*) should work for you in your case.
There are some more ways to import python into python, which you might want to check out.

How to import and use a module with one line

I have this code that loads the natural gas storage numbers from the internet.
from urllib.request import urlopen
print(int(str(urlopen("http://ir.eia.gov/ngs/wngsr.txt").read()).split("\\n")[4].split(" ")[2]))
How could I do this in one line? More specifically, I was wondering how I could get rid of the import line and do something like this:
print(int(str(urllib.request.urlopen("http://ir.eia.gov/ngs/wngsr.txt").read()).split("\\n")[4].split(" ")[2]))
(I changed the urlopen call to urllib.request.urlopen. It would be sort of like Java, if you use the fully qualified name, you don't need an import statement.)

When trying out the suggestion by Zizouz212, I found this works
print(int(str(__import__('urllib').request.urlopen("http://ir.eia.gov/ngs/wngsr.txt").read()).split("\\n")[4].split(" ")[2]))

You always need the import, however you can still use semi-colons to separate statements:
from urllib.request import urlopen; print(int(str(urllib.request.urlopen("http://ir.eia.gov/ngs/wngsr.txt").read()).split("\\n")[4].split(" ")[2]))
# note the semi-colon ^