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Use different Python version with virtualenv
...Docs suggest creating the virtual environment with the following command:
python3 -m venv <myenvname>
Please note that venv does not permit creating virtual environments with other versions of Python. For that, install and use the virtualenv package.
Obsolete information
The pyvenv scri...
Why is it slower to iterate over a small string than a small list?
...check what to return.
List indexing is remarkably fast.
>>> python3 -m timeit '[x for x in "abc"]'
1000000 loops, best of 3: 0.388 usec per loop
>>> python3 -m timeit '[x for x in ["a", "b", "c"]]'
1000000 loops, best of 3: 0.436 usec per loop
This disagrees with what you'...
ImportError: No module named matplotlib.pyplot
...
In python3, a separate installation of matplotlib using python3 -m pip install matplotlib solved the error. Tested on Ubuntu 16.04.
– vineeshvs
Jun 5 '19 at 6:22
...
How can I use Homebrew to install both Python 2 and 3 on Mac?
...rew:
For Python 2.x:
brew install python
For Python 3.x:
brew install python3
Now, you will have both the versions installed in your machine. When you want to use version 2, use the python executable. When you want to use version 3, use the python3 executable.
...
ImportError: No module named requests
...
OSX/Linux
Use $ sudo pip install requests (or pip3 install requests for python3) if you have pip installed. If pip is installed but not in your path you can use python -m pip install requests (or python3 -m pip install requests for python3)
Alternatively you can also use sudo easy_install -U re...
bash: pip: command not found
...
2020 Update:
For current Debian/Ubuntu, use
apt-get install python3-pip
to install pip3.
Old 2013 answer (easy_install is now deprecated):
Use setuptools to install pip: sudo easy_install pip
(I know the above part of my answer is redundant with klobucar's, but I can't add comments ...
Why is there no xrange function in Python3?
Recently I started using Python3 and it's lack of xrange hurts.
6 Answers
6
...
Relative imports in Python 3
...
myothermodule.py
...with a mymodule.py like this...
#!/usr/bin/env python3
# Exported function
def as_int(a):
return int(a)
# Test function for module
def _test():
assert as_int('1') == 1
if __name__ == '__main__':
_test()
...a myothermodule.py like this...
#!/usr/bin/env...
解决python3报错：TypeError: a bytes-like object is required, not \'str...
解决python3报错：TypeError: a bytes-like object is required, not 'str'问题原因：python3和Python2在套接字返回值解码上有区别，也就是说报错的这段代码在python2上可以正常使用。解决思路：python bytes和str两种类型可以通过函数encode()和decode() ...
Determine Whether Integer Is Between Two Other Integers?
...
looks like in python3.5.2, range is ~10x slower than the if statement, with speed constant in regard to range check value...thus most likely difference due to function overhead.
– amohr
Nov 10 '16 at...