Replacing every odd 'comma' with a 'colon' with in a list-CodePudding

I have a list of integer like so:

print(list) = 
[3584, 71943, 74593, 78252, 79205, 85318, 86152, 92030, 93207, 96977, 100464, 102041]

This is a list of ranges of index values so I want to replace every odd occurrence of comma with a colon like so:

[3584: 71943, 74593: 78252, 79205: 85318, 86152: 92030, 93207: 96977, 100464: 102041]

I have tried several regex examples such as:

re.sub(r'(\b\d{1,2}),',r'\g<1>:',result)

but I keep getting: TypeError: expected string or bytes-like object

I have also tried converting this list to a string then performing the regex solution above but it still did not work.

Any help would be greatly appreciated!

CodePudding user response：

You don't need Regex for that. You already have Python code, so just use Python code to convert the list into a dictionary.

numbers = [3584, 71943, 74593, 78252, 79205, 85318, 86152, 92030, 93207, 96977, 100464, 102041]
dictionary = {}
for i in range(0, len(numbers) - 1, 2):
    dictionary[numbers[i]] = numbers[i   1]
print(dictionary)

Result:

{3584: 71943, 74593: 78252, 79205: 85318, 86152: 92030, 93207: 96977, 100464: 102041}

Note:

don't use the name list, because it shadows the Python type list

CodePudding user response：

Assuming you want string outputs, and not a dictionary or something similar:

ls = [3584, 71943, 74593, 78252, 79205, 85318, 86152, 92030, 93207, 96977, 100464, 102041]
paired = [f"{ls[i]}: {ls[i 1]}" for i in range(0, len(ls), 2)]

As noted, your input is a list of ints, and your desired output is invalid in Python. So this is a guess as to what you want - the other reasonable guess would be a dictionary of key-value pairs mapping from int to int.

ls = [3584, 71943, 74593, 78252, 79205, 85318, 86152, 92030, 93207, 96977, 100464, 102041]
paired = {ls[i]: ls[i 1] for i in range(0, len(ls), 2)}

Essentially, the colon in Python has semantic meaning in certain places. In a dictionary, for instance, in the second solution above, it defines a relationship between a key and a value. It does not have semantic meaning and is therefor an error inside a list - unless it's encapsulated in a string, in which case it's just another character.

CodePudding user response：

Your output is suit for dictionary type. You could use dictionary comprehension with zip function to slice the list from index 0 with 2 step (even) and from index 1 with 2 step (odd) as key and value pairs.

lst = [3584, 71943, 74593, 78252, 79205, 85318, 86152, 92030, 93207, 96977, 100464, 102041]
dct = {k: v for k, v in zip(lst[0::2], lst[1::2])}
print(dct)

# {3584: 71943, 74593: 78252, 79205: 85318, 86152: 92030, 93207: 96977, 100464: 102041}