Blog
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Pandas iloc vs loc: Selecting series values by position
Retrieve from a Python Pandas series by position, rather than the index, with iloc:
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Pandas .loc with a list returns a series, not a scalar
Pass a list to .loc on a Python Pandas series, and get a series back:
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Pandas Series duplicate index labels: When .loc returns a Series
The index in a Python Pandas series feels like a dict keys. But the keys can repeat:
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Pandas Series indexing: Why .loc beats [] for retrieval
To retrieve from a Python Pandas series, you can use [] to retrieve items. But don’t! In a series, [] uses the index. In a data frame, [] uses the column names. Confusing! Besides, .loc does everything [] does, but with more options and flexibility.
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Pandas set_axis: Replacing a Series index without mutating it
You can set a Python Pandas series index with set_axis. This returns a new series with the new index applied: s.index # still Index([‘a’, ‘b’, ‘c’], dtype=’str’)
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Pandas Series index: Change it by assigning to s.index
Want to change the index of a Python Pandas series? Just assign to it:
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Pandas Series index: Setting labels instead of RangeIndex
By default, a Python Pandas series has a RangeIndex, like a string or list: Set an index like this:
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isinstance vs type(): The safer way to check Python types
Is a Python value of a particular type? It’s tempting to say: Far better to say: Why?– Works with subclasses– Second argument can be a tuple of possibilities
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Python inheritance: When to use it and when to prefer composition
When should you use inheritance in Python? – An existing class mostly does what you want– Inheriting reduces your work — you only define differences– It’s an IS-A relationship, not just HAS-A– Otherwise: prefer composition. Remember: Inheritance is a tool, not a default.
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Python metaclasses: How they work and when to use a decorator instead
What is a Python metaclass? – A subclass of type– Classes can be instances of a metaclass, rather than type– The metaclass’s __init__ sets attributes and methods Realistically, you should probably use a decorator instead of a metaclass. (But they’re fun to play with!)