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- List of zeros in python - Stack Overflow
How can I create a list which contains only zeros? I want to be able to create a zeros list for each int in range(10) For example, if the int in the range was 4 I will get: [0,0,0,0] and for 7:
- slice - How slicing in Python works - Stack Overflow
The first way works for a list or a string; the second way only works for a list, because slice assignment isn't allowed for strings Other than that I think the only difference is speed: it looks like it's a little faster the first way Try it yourself with timeit timeit () or preferably timeit repeat ()
- python - if else in a list comprehension - Stack Overflow
Since a list comprehension creates a list, it shouldn't be used if creating a list is not the goal; it shouldn't be used simply to write a one-line for-loop; so refrain from writing [print(x) for x in range(5)] for example
- Use a list of values to select rows from a Pandas dataframe
Use a list of values to select rows from a Pandas dataframe Asked 12 years, 11 months ago Modified 4 months ago Viewed 1 8m times
- TypeError: list indices must be integers or slices, not str
Another common mistake is to initialize a list but try to assign values to it using a key The initialization probably happened dynamically and it's not clear later on that it's in fact a list For example, in the following case, d is initialized as a list but there's an attempt to add a key-value pair to it
- How to cast List lt;Object gt; to List lt;MyClass gt; - Stack Overflow
You can't directly cast List to List because Java generics are invariant This means that List is not the same as List, even though Customer is a subtype of Object
- How do I make a flat list out of a list of lists? - Stack Overflow
If your list of lists comes from a nested list comprehension, the problem can be solved more simply directly by fixing the comprehension; please see How can I get a flat result from a list comprehension instead of a nested list? The most popular solutions here generally only flatten one "level" of the nested list See Flatten an irregular (arbitrarily nested) list of lists for solutions that
- List unique values in a Pandas dataframe - Stack Overflow
You can get the unique values in the whole df with this one-liner: pd Series(df values flatten()) unique() You basically transform your df to a numpy array, flatten and come back to a pandas Series, so you can use unique() However, types might be transformed along the way if you have multiple types in your original df, so be careful
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