将str元组列表转换为int元组列表？

Question

I have a list of tuples which I would like to import into a dictionary. Those tuples consist of two strings. I would like to convert those tuples into integers. ie

myList = ['0,1', '0,2', '0,3']

The resulting list should be:

resList = [(0,1), (0,2), (0,3)]

I have tried using:

list(map(int, myList))

But that doesn't seem to work.

Answer 1

You could use eval function to get the tuples, like this. Works in both python2, and python3.

>>> myList = ['0,1', '0,2', '0,3']
>>> list(map(eval, myList))
[(0, 1), (0, 2), (0, 3)]

Answer 2

You also need to split your strings by ',' .

>>> [tuple(map(int, s.split(','))) for s in myList]                                                                               
[(0, 1), (0, 2), (0, 3)]

Another option is to use the csv module.

>>> import csv                                                                                                                    
>>> list(csv.reader(myList))                                                                                                      
[['0', '1'], ['0', '2'], ['0', '3']]
>>> [tuple(map(int, row)) for row in csv.reader(myList)]                                                                          
[(0, 1), (0, 2), (0, 3)]

If it's not terribly important the the inner elements of the result are tuples and that they are of type int , we can simplify the csv solution to

>>> list(csv.reader(myList, quoting=csv.QUOTE_NONNUMERIC))                                                                        
[[0.0, 1.0], [0.0, 2.0], [0.0, 3.0]]

---

~edit~

thelogicalkoan's answer reminded me of ast.literal_eval which provides the most elegant (and safe) solution here.

>>> from ast import literal_eval                                                                                                  
>>> [literal_eval(x) for x in myList]                                                                                             
[(0, 1), (0, 2), (0, 3)]

Answer 3

An alternative solution is to use ast.literal_eval (instead of eval which can be considered unsafe):

>>> import ast
>>> ast.literal_eval('0,1')
(0, 1)

So, you can do:

>>> my_list = ['0,1', '0,2', '0,3']
>>> result = [ast.literal_eval(x) for x in my_list]
>>> result
[(0, 1), (0, 2), (0, 3)]

Answer 4

str.partition can be used to do this.

>>> [(int(x), int(y)) for x, _, y in (z.partition(',') for z in myList)]
[(0, 1), (0, 2), (0, 3)]

The generator expression (z.partition(',') for z in myList) produces the output of str.partition on each element of the list, and then we call int on the parts that we require.

Answer 5

This is a different option:

myList = ['0,1', '0,2', '0,3']

def tSet(list): 
    return tuple([int(i) for i in list])

resList  = [tSet(i.split(",")) for i in myList]

print(resList) #Output: [(0, 1), (0, 2), (0, 3)]