Python programming assistance [duplicate] - python

This question already has answers here:
Closed 10 years ago.
Possible Duplicate:
Why do people write #!/usr/bin/env python on the first line of a Python script?
I am currently teaching myself Python and I have a question about python. In many examples of Python, I've seen the same line of code at the top:
#!/usr/bin/env python
My question is what purpose does the code above serve, and why is it necessary? So far, I've been practicing Python code without this line of code. If someone could explain this to me, it would help a lot. Thanks in advance.

#!/usr/local/bin/env python
You are specifying the location to the python executable in your machine, that the rest of the script needs to be interpreted with.
You are pointing to python is located at /usr/local/bin/python.
Python is not always installed at '/usr/local/bin/python'. You can also call different python versions by #!/path/to/your/python/version.

It is describing the location of the python install that your code should use. See here and here.

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Is there a way to run Python code without downloading Python? [duplicate]

This question already has answers here:
How can I convert a .py to .exe for Python?
(8 answers)
Closed 1 year ago.
My internship has asked me to make my code executable for people who do not have Python downloaded. I can run parts of it on online Python compilers, but it uses different libraries that are not supported on those compilers. My program opens a .csv file specified by the user and filters it and writes the new data to a new .csv file. To implement the code online, I think I would need to learn JavaScript? Is there any other alternative? I appreciate any guidance provided!
You can create a standalone executable that includes your python script + all necessary files to run it. The users then just run ".exe" file without need to download and setup python environment. A great library to do it is cx-freeze
There is many online python runner. Example https://www.programiz.com/python-programming/online-compiler/

How do I see how my program is executed line by line [duplicate]

This question already has answers here:
How to step through Python code to help debug issues?
(15 answers)
Closed 3 years ago.
I am trying to learn the basics of programming using python, and I am getting to the point where I have to deal with if statements and for loops. The thing is that I am getting a bit confused as to how my code is running. Is there a way to see how my code is being executed line by line; I feel that that would deepen my understanding of why code has to be written a certain way in order for computers to understand what I am trying to accomplish. I dont know if my question makes any sense to you guys, but I hope you can help me. Thanks a lot in advance.
You can use an interactive debugger. Some Python IDEs provide it.
You may want to give VS Code a try. Take a look at the debugger part of the tutorial.
What you are looking for is called a debugger. You can find some online, for example here: https://www.onlinegdb.com/online_python_debugger . Alternatively you can use pdb, the python debugger (the above link is just a friendly wrapper around it), directly from the command line, but if you are new to python and programming I wouldn't recommand it.
Try pdb.
python -m pdb script.py
More information on How to step through Python code to help debug issues?.
pdb documentation here.

How would you make a python shell in python? [duplicate]

This question already has answers here:
How to drop into REPL (Read, Eval, Print, Loop) from Python code
(7 answers)
Closed 6 years ago.
How would you make the IDLE shell, using nothing but Python code? Now, I understand the beggingins, like a simple exec(raw_input('>> ')), but how would you get if and else statments, or for and while loops to work?
while 1==1:
is considered invalid syntax. How would you prevent that?
The suggested thread isn't nearly the same thing, as all of the answers but one answer how to run a python program from a python program. One of the answers points kinda of like what I'm asking, but it would still fail in an if and else statement, or a while or for loop.
The source code for IDLE is in the Python standard library, under the idlelib package. You can look at the source to see how they implement everything.
idlelib is a lot of code, so it might be overwhelming to try to go through it. The code module provides a Python implementation of Python's interactive mode; you could go through the source code for that to get an idea of how you could do things.

Can I block others from seeing my Python code? [duplicate]

This question already has answers here:
Undecompilable Python
(2 answers)
Closed 9 years ago.
Can I block others from seeing my code? I'm working on something in Python. As I save it, it's a (.py) and everyone can right-click and see the code. This is unlike C where I generate an .exe that you can't simply (!) read.
You can read the assembly code generated by the process of the compilation in C. The code is not hidden : it's a bit more complex to read, because it is ASM. But it is totally and definitively not hidden :)
Python is made by Open Source community, so the idea is not about hiding your code. If ever you want to make a .exe from a Python code, you can have a try to Py2Exe or Freeze :
http://www.py2exe.org/
http://wiki.python.org/moin/Freeze
Cheers,
K.

Which Python IDE [duplicate]

This question already has an answer here:
Closed 11 years ago.
Possible Duplicate:
What IDE to use for Python?
Hi recently started looking at Python, basically for scripting, so far I've been doing exercises from the web, which is OK. I'm using gEdit and its fine. but I'm curious to know what is a good IDE for python, that will still allow me to discover. One of the things I'm used to in Visual Studio is code completion,code snippets and tips, so when you type FOO then CTRL+SPACE you get to see what methods,properties etc are available for FOO. You can select a method press F1 and get HELP on its usage. Really helps discovery and learning. Can anyone recommend a good IDE preferably FREE that works well on windows(Linux is optional) and has features such as code completion,code snippets,code tips
You might want to try Vim or Eclipse.

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