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I want to define (create) and use different variable (using suffix) through loop (specially for loop)

I want to create multiple variable through for loop to further use and compare in the program.
Here is the code -
for i in range(0,len(Header_list)):
(f'len_{i} = {len(Header_list[i]) + 2 }')
print(len_0);print(f'len{i}')
for company in Donar_list:
print(company[i],f"len_{i}")
if len(str(company[i])) > len((f"len_{i}")) :
(f'len_{i}') = len(str(company[i]))
print(f"len_{i}")
But what is happening, though I managed to create variable len_0,len_1,len_2... in line-2, in line - 3 I also can print len_0..etc variable by only using print(len_0), but I can't print it the values of these by - print(f'len_{i}')
In line 5 I also can't compare with the cofition with my intension. I want it do create variable and compare it further when as it necessary, in this case under for loop.What should I do now? I am a beginner and I can do it using if statement but that wouldn't be efficient, also my intention is not to create any **data structure ** for this.
I don't know whether I could manage to deliver you what I am trying to say. Whatever I just wanna create different variable using suffix and also comprare them through for loop in THIS scenario.

Instead of dynamically creating variables, I would HIGHLY recommend checking out dictionaries.
Dictionaries allow you to store variables with an associated key, as so:
variable_dict = dict()
for i in range(0,len(Header_list)):
variable_dict[f'len_{i}'] = {len(Header_list[i]) + 2 }
print(len_0)
print(f'len{i}')
for company in Donar_list:
print(company[i],f"len_{i}")
if len(str(company[i])) > len(variable_dict[f"len_{i}"]) :
variable_dict[f'len_{i}'] = len(str(company[i]))
print(f"len_{i}")
This allows you to access the values using the same key:
len_of_4 = variable_dict['len_4']
If you REALLY REALLY need to dynamically create variables, you could use the exec function to run strings as python code. It's important to note that the exec function is not safe in python, and could be used to run any potentially malicious code:
for i in range(0,len(Header_list)):
exec(f'len_{i} = {len(Header_list[i]) + 2 }')
print(len_0);print(f'len{i}')
for company in Donar_list:
print(company[i],f"len_{i}")
if exec(f"len(str(company[i])) > len(len_{i})"):
exec(f'len_{i} = len(str(company[i]))')
print(f"len_{i}")

In python everything is object so use current module as object and use it like this
import sys
module = sys.modules[__name__]
Header_list=[0,1,2,3,4]
len_ = len(Header_list)
for i in range(len_):
setattr(module, f"len_{i}", Header_list[i]+2)
print(len_0)
print(len_1)

Header_list=[0,1,2,3,4]
for i in range(0,5):
exec(f'len_{i} = {Header_list[i] + 2 }')
print(f'len{i}')
output:
len0
len1
len2
len3
len4

How to traverse dictionary keys in sorted order

I am reading a cfg file, and receive a dictionary for each section. So, for example:
Config-File:
[General]
parameter1="Param1"
parameter2="Param2"
[FileList]
file001="file1.txt"
file002="file2.txt" ......
I have the FileList section stored in a dictionary called section. In this example, I can access "file1.txt" as test = section["file001"], so test == "file1.txt". To access every file of FileList one after the other, I could try the following:
for i in range(1, (number_of_files + 1)):
access_key = str("file_00" + str(i))
print(section[access_key])
This is my current solution, but I don't like it at all. First of all, it looks kind of messy in python, but I will also face problems when more than 9 files are listed in the config.
I could also do it like:
for i in range(1, (number_of_files + 1)):
if (i <= 9):
access_key = str("file_00" + str(i))
elif (i > 9 and i < 100):
access_key = str("file_0" + str(i))
print(section[access_key])
But I don't want to start with that because it becomes even worse. So my question is: What would be a proper and relatively clean way to go through all the file names in order? I definitely need the loop because I need to perform some actions with every file.

Use zero padding to generate the file number (for e.g. see this SO question answer: https://stackoverflow.com/a/339013/3775361). That way you don’t have to write the logic of moving through digit rollover yourself—you can use built-in Python functionality to do it for you. If you’re using Python 3 I’d also recommend you try out f-strings (one of the suggested solutions at the link above). They’re awesome!

If we can assume the file number has three digits, then you can do the followings to achieve zero padding. All of the below returns "015".
i = 15
str(i).zfill(3)
# or
"%03d" % i
# or
"{:0>3}".format(i)
# or
f"{i:0>3}"

Start by looking at the keys you actually have instead of guessing what they might be. You need to filter out the ones that match your pattern, and sort according to the numerical portion.
keys = [key for key in section.keys() if key.startswith('file') and key[4:].isdigit()]
You can add additional conditions, like len(key) > 4, or drop the conditions entirely. You might also consider learning regular expressions to make the checking more elegant.
To sort the names without having to account for padding, you can do something like
keys = sorted(keys, key=lambda s: int(s[4:]))
You can also try a library like natsort, which will handle the custom sort key much more generally.
Now you can iterate over the keys and do whatever you want:
for key in sorted((k for k in section if k.startswith('file') and k[4:].isdigit()), key=lambda s: int(s[4:])):
print(section[key])
Here is what a solution equipt with re and natsort might look like:
import re
from natsort import natsorted
pattern = re.compile(r'file\d+')
for key in natsorted(k for k in section if pattern.fullmatch(k)):
print(section[key])

How do I split and reconstruct a variable name while holding its original value

Is it possible to split variables that have already been assigned values, and re-piece them back together to hold those same previous values?
For Example:
URLs.QA.Signin = 'https://qa.test.com'
TestEnvironment = 'QA'
CurrentURL = 'URLs.' + TestEnvironment + '.Signin'
print(CurrentURL)
Outputs as: 'URLs.QA.Signin'
but I would like it to:
Output as: 'https://qa.test.com'
The purpose is so I can plug in any value to my 'TestEnvironment' variable and thus access any of my massive list of URL's with ease =P
I am green with Python. Your time and efforts are greatly appreciated! =)
Based upon evanrelf's answer, I tried and loved the following code!:
This is exactly what i'm looking for, I might be over complicating it, any suggestions to clean up the code?
urls = {}
environment = 'qa'
district = 'pleasanthill'
url = environment + district
urls[url] = 'https://' + environment + '.' + district + '.test.com'
print(urls[url])
Output is: https://qa.pleasanthill.test.com

I would recommend you look into Python's dictionaries.
urls = {}
urls['qa'] = 'https://qa.test.com'
test_environment = 'qa'
print(urls[test_environment])
// => https://qa.test.com

I believe to my comprehension that you are trying to input a string and get a new string (the url) back. The simplest answer that I can understand is to use a dictionary. An example of this is by simply doing
URLS = {'sheep' : 'wool.com', 'cows' : 'beef.com'}
either this or by using two arrays and referencing a common index, but who wants to do that :p

How to automatically create list with 550 elements each, without the need to rename each one manually?

I would heavily need your help to simplify a code that allows me to have a data analysis on salesforce leads.
I have the following dataframes, which as you can see are split due to python limit on managing more than 550 objects in a single list.
Iterlist = list()
for x in range(0, int(len(List)/550)+1):
m = List[550*x: 550*x+550]
Iterlist.append(m)
Iterlist0= pd.DataFrame(Iterlist[0])
Iterlist1= pd.DataFrame(Iterlist[1])
Iterlist2= pd.DataFrame(Iterlist[2])
...and so on until the initial longer list is split
...
converted in the following lists for formatting reasons:
A= Iterlist0["Id"].tolist()
mylistA = "".join(str(x)+ "','" for x in A)
mylistA = mylistA[:-2]
mylistA0 = "('" + mylistA + ")"
B = Iterlist1["Id"].tolist()
mylistB = "".join(str(x)+ "','" for x in B)
mylistB = mylistB[:-2]
mylistB1 = "('" + mylistB + ")"
C = Iterlist2["Id"].tolist()
mylistC = "".join(str(x)+ "','" for x in C)
mylistC = mylistC[:-2]
mylistC2 = "('" + mylistC + ")"
and so on...
...
I want to create a loop that allows me to query from salesforce each of the lists using the following code template for example:
queryA='SELECT '+cols[1]+', '+cols[2]+', '+cols[3]+', '+cols[4]+', '+cols[5]+', '+cols[6]+', '+cols[7]+', '+cols[8]+' FROM LeadHistory WHERE LeadId IN '+mylistA0
and then finally:
sf = Salesforce(username='xxx', password='xxx', security_token='xxx')
leadhistory = sf.query_all(queryA)
I don´t want to write over and over numerous dataframes with specific names, lists and queries in order to get to the result. I would like to have a line for each of the codes written above, and let python automatically update the naming according to the number of 550 elements list.
I am new to this programming language and any tip would help me a lot. I think is possible to simplify it a lot but no idea how can be done.
Thanks in advance!

Merging lists obtained by a loop

I've only started python recently but am stuck on a problem.
# function that tells how to read the urls and how to process the data the
# way I need it.
def htmlreader(i):
# makes variable websites because it is used in a loop.
pricedata = urllib2.urlopen(
"http://website.com/" + (",".join(priceids.split(",")[i:i + 200]))).read()
# here my information processing begins but that is fine.
pricewebstring = pricedata.split("},{")
# results in [[1234,2345,3456],[3456,4567,5678]] for example.
array1 = [re.findall(r"\d+", a) for a in pricewebstring]
# writes obtained array to my text file
itemtxt2.write(str(array1) + '\n')
i = 0
while i <= totalitemnumber:
htmlreader(i)
i = i + 200
See the comments in the script as well.
This is in a loop and will each time give me an array (defined by array1).
Because I print this to a txt file it results in a txt file with separate arrays.
I need one big array so it needs to merge the results of htmlreader(i).
So my output is something like:
[[1234,2345,3456],[3456,4567,5678]]
[[6789,4567,2345],[3565,1234,2345]]
But I want:
[[1234,2345,3456],[3456,4567,5678],[6789,4567,2345],[3565,1234,2345]]
Any ideas how I can approach this?

Since you want to gather all the elements in a single list, you can simply gather them in another list, by flattening it like this
def htmlreader(i, result):
...
result.extend([re.findall(r"\d+", a) for a in pricewebstring])
i, result = 0, []
while i <= totalitemnumber:
htmlreader(i, result)
i = i + 200
itemtxt2.write(str(result) + '\n')
In this case, the result created by re.findall (a list) is added to the result list. Finally, you are writing the entire list as a whole to the file.
If the above shown method is confusing, then change it like this
def htmlreader(i):
...
return [re.findall(r"\d+", a) for a in pricewebstring]
i, result = 0, []
while i <= totalitemnumber:
result.extend(htmlreader(i))
i = i + 200