In r code, the sequence of integers from 1 to 4:
1:4
How can I replicate this in python 3? The use case is selecting from a pandas dataframe using iloc:
df.iloc[1:4]
5 Answers
You can use
mylist=list(range(1,5))
print(mylist)
list() converts given range object into list
3 Comments
chepner
There is no
range object, because your code produces a syntax error.
Hetal Thaker
Yeah i agree, there should be , instead of :
Hetal Thaker
Now you may check this please.
Use range(1, 5) for giving you that set of integers from 1 to 4 (inclusive of both)
Comments
In Python, in order to generate a range of numbers use the function range.
range(1, 5)
This will generate numbers from 1 to 4. If you are in Python 2, range will give you a list, and if you are in Python 3, it will give you a range object.
If you are in Python 3, and you want a list, just use the list function to convert your range to a list
>>> list(range(1, 5)
[1, 2, 3, 4]
1 Comment
DDDD
Thank you. I'm used to python 2 range. What if I want a list of numbers and not range object?
Python's slicing syntax doesn't produce a range of integers; it produces one or more slice objects which are passed to the __getitem__ method of the appropriate type. That is,
df.iloc[1:4]
is equivalent to either
def.iloc[slice(1,4)]
or
df.iloc.__getitem__(slice(1,4))
Comments
To generate a range of number from 1 to 4 (inclusive), use: range(1, 5) or range(1, 4+1)
Just a few things to note:
The code
range(x, y)generates a range from (and including)xup to (but not including)y. If you want to includey, add 1 to it (as I did above).range(x, y)works a bit differently in Python 2 vs. Python 3. I won't go into the details here, but I recommend using Python 3 (which hopefully you're already using).range(x)is will generate a range from (and including) zero up to (but not including)x. Sorange(x)is basically the same asrange(0, x).The
rangefunction will generate arangeobject; that is, it doesn't actually create alistof all the integers betweenxandy. If you do want alistof integers betweenxandy, use this code:some_list = list(range(x, y))
However, if you're looking to pull out a slice of values out of a sequential container, this might work:
from itertools import islice
values = islice(df.iloc, 1, 5) # returns an iterator
values = list(values) # extracts the values from the iterator into a list
range(1, 5)df.iloc[1:4]is essentially just syntactic sugar fordf.iloc[slice(1,4)]; it's unrelated to the generation of an actual sequence of integers. It's up to the particular implementation of__getitem__that receives thatsliceobject to decide how exactly to treat it.