ImportError: No module named pip
had the same problem. My solution: For Python 3 For Python 2
Python
TypeError: ‘str’ object is not callable (Python)
This is the problem: You are redefining what str() means. str is the built-in Python name of the string type, and you don’t want to change it. Use a different name for the local variable, and remove the global statement.
Truth value of a Series is ambiguous. Use a.empty, a.bool(), a.item(), a.any() or a.all()
The or and and python statements require truth-values. For pandas these are considered ambiguous so you should use “bitwise” | (or) or & (and) operations: These are overloaded for these kind of datastructures to yield the element-wise or (or and). Just to add some more explanation to this statement: The exception is thrown when you want to get the bool of a pandas.Series: What you hit was a place where the operator implicitly converted … Read more
How do I update Anaconda?
What 95% of people actually want In most cases what you want to do when you say that you want to update Anaconda is to execute the command: (But this should be preceeded by conda update -n base conda so you have the latest conda version installed) This will update all packages in the current environment to the latest version — … Read more
numpy max vs amax vs maximum
np.max is just an alias for np.amax. This function only works on a single input array and finds the value of maximum element in that entire array (returning a scalar). Alternatively, it takes an axis argument and will find the maximum value along an axis of the input array (returning a new array). The default behaviour of np.maximum is to take two arrays and compute … Read more
How do I list all files of a directory?
os.listdir() will get you everything that’s in a directory – files and directories. If you want just files, you could either filter this down using os.path: or you could use os.walk() which will yield two lists for each directory it visits – splitting into files and dirs for you. If you only want the top directory you can break the first time it yields or, shorter:
How to send an email with Python?
I recommend that you use the standard packages email and smtplib together to send email. Please look at the following example (reproduced from the Python documentation). Notice that if you follow this approach, the “simple” task is indeed simple, and the more complex tasks (like attaching binary objects or sending plain/HTML multipart messages) are accomplished very rapidly. For sending email … Read more
Purpose of “%matplotlib inline”
%matplotlib is a magic function in IPython. I’ll quote the relevant documentation here for you to read for convenience: IPython has a set of predefined ‘magic functions’ that you can call with a command line style syntax. There are two kinds of magics, line-oriented and cell-oriented. Line magics are prefixed with the % character and work much like … Read more
Relative imports in Python 3
unfortunately, this module needs to be inside the package, and it also needs to be runnable as a script, sometimes. Any idea how I could achieve that? It’s quite common to have a layout like this… …with a mymodule.py like this… …a myothermodule.py like this… …and a main.py like this… …which works fine when you run main.py or mypackage/mymodule.py, but fails with mypackage/myothermodule.py, due to … Read more
How does collections.defaultdict work?
Usually, a Python dictionary throws a KeyError if you try to get an item with a key that is not currently in the dictionary. The defaultdict in contrast will simply create any items that you try to access (provided of course they do not exist yet). To create such a “default” item, it calls the … Read more