What does '\' mean when declaring a variable? [duplicate] - python

This question already has answers here:
What does a backslash by itself ('\') mean in Python? [duplicate]
(5 answers)
What is the purpose of a backslash at the end of a line?
(2 answers)
Closed 1 year ago.
While I was searching code from the internet about YouTube data analysis, I found code like this:
df_rgb2['total_sign_comment_ratio'] = df_rgb2['total_number_of_sign'] / df_rgb2['comment_count']
total_sign_comment_ratio_max = df_rgb2['total_sign_comment_ratio'].replace([np.inf, -np.inf], 0).max()
df_rgb2['total_sign_comment_ratio'] = \
df_rgb2['total_sign_comment_ratio'].replace([np.inf, -np.inf], total_sign_comment_ratio_max*1.5)
and I was wondering why the analyst used the expression:
df_rgb2['total_sign_comment_ratio'] = \
because whether I apply that code or not, the result is same.
I tried to find the meaning of '\' but all I have got is how to use '\' when printing out the result.

\ is usually used to make a piece of code go on onto multiple lines. If you where to just press enter and continue to write code a line below for example declaring a variable, it would count as an error.
You use this when you need to tidy up code or when your working window is too small for some reason.
See: https://developer.rhino3d.com/guides/rhinopython/python-statements/

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How to format a string in Python source code for improved readability [duplicate]

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I'm building a rather long file path, like so:
file_path = f"{ENV_VAR}/my_dir/{foo['a']}/{foo['b']}/{bar.date()}/{foo['c']}.json"
This is a simplified example. The actual path is much longer.
To make this line shorter and more readable in code, I have tried the following:
file_path = f"{ENV_VAR}/my_dir\
/{foo['a']}\
/{foo['b']}\
/{bar.date()}\
/{foo['c']}.json"
This works but also affects the actual string in my program.
More specifically, the linebreaks are added to the string value itself, which is undesirable in this case. I only want to change the formatting of the source code.
Is it possible to format the string without affecting the actual value in my program?

Is there a way to write single backslash within lists? [duplicate]

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Why does printing a tuple (list, dict, etc.) in Python double the backslashes?
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Closed 1 year ago.
enter image description here
is there a way to print single backslash within list?
Regarding the first version of your question, I wrote this:
First, this expression x='\' isn't right in Python in python. you should rather puth it this way: x='\\', since back slash is a special character in python.
Second, try this:
l=['\\'] print(l)
This will print: ['\\']
But when you execute this: print(l[0]), it renders this '\'. So basically, this ['\\'] is the way to print a backslash within a list.

What is the Python ` symbol [duplicate]

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What do backticks mean to the Python interpreter? Example: `num`
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Lots of old python code I look in has this ` symbol around a lot of stuff, what does it do? Now it is not considered valid syntax, obviously.
And I don't think it is just another string identifier, its sometimes wrapped around functions in the code I'm looking at.
Any help will be appreciated.

Python finding variable characters in a string with RE? [duplicate]

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Hey I need to search for variable data in a console from a page source
The data will be shown like this:
"data":[13,17]
It will vary a lot with the amount of units inside the table. I have tried out several RE expressions, but the closest I have come to a result, is with a fixed amount of units.
self.driver.get("website.com")
apidata = self.driver.page_source
print(apidata)
datasetbasic = re.search('"data":[[0-99,0-99]+', apidata)
print(datasetbasic)
Instead of having it as a fixed amount, how do I capture anything that is inside the data table?
Before you ask, I cannot use xpath or any other selenium calls to capture this data directly from the webpage (I think), because the element is from a graph, where the data is only visible in the actual console.
Any help is appreciated

Substitute variable in a command in Python [duplicate]

This question already has answers here:
Variable interpolation in Python [duplicate]
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I'm pretty novice in Python scripting and was trying to run an API call with some dynamic values passed.
A simple idea about the code is, it gets two datetimes in epoch(10 second interval)and calls an API to do a function.
import commands
end = str(datetime.datetime.now().strftime("%s"))
start = str((datetime.datetime.now() - datetime.timedelta(seconds=10)).strftime("%s"))
output = commands.getstatusoutput("curl 'http://my-api-url/object?param1=1&start=$start&end=$end&function=average'")
It doesn't work as the variables start and end are not getting expanded/substituted.
As you see, I come from bash scripting and tried looking on several variable substitution commands from web, but nothing specific found to my case here.
Use str.format
Ex:
import commands
end = str(datetime.datetime.now().strftime("%s"))
start = str((datetime.datetime.now() - datetime.timedelta(seconds=10)).strftime("%s"))
output = commands.getstatusoutput("curl 'http://my-api-url/object?param1=1&start={start}&end={end}&function=average'".format(start=start, end=end))
In Python, you can concatenate strings using the '+' operator.
In your case you could write:
output = commands.getstatusoutput("curl 'http://my-api-url/object?param1=1&start=" + start + "&end=" + end + "&function=average'")

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