(When list mix with text & numbers) How to convert numbers in each small list into numeric instead of string within that big list in python?

Question

The list is mixed with both text and numbers. And so far they all have ' ' symbol, means they are all string? So how to convert numbers in each small list into numeric instead of string within that big list in python?

This is what I have:

wholeList = [ ['apple','1','2'],['banana','2','3'],['cherry', '3','4'],['downypitch', '4','5'] ]

This is what I want: text such as apple have type string, while the numbers such as 2 have type numeric

newList = [ [apple,1,2],[banana,2,3],[cherry, 3,4],[downypitch, 4,5]]

This is what I tried:

newList = []

for t in wholeList:
    for j in num_part:
        new_part = int(j)
        newList.append(new_part)

print(newList)

However, this gives me something like this:

[1, 2, 2, 3, 3, 4, 4, 5]

Answer 1

Based on your code, I am assuming that 0-th entry remains to be string, while 1st, 2nd, ... are to be converted into integers.

You can use list comprehension as follows:

whole_list = [ ['apple','1','2'],['banana','2','3'],['cherry', '3','4'],['downypitch', '4','5'] ]

new_list = [[sublst[0], *map(int, sublst[1:])] for sublst in whole_list]
print(new_list) # [['apple', 1, 2], ['banana', 2, 3], ['cherry', 3, 4], ['downypitch', 4, 5]]

Answer 2

Here's an approach that allows for the number strings being anywhere in the sublists and for the sublists to be of any length:

wholeList = [ ['apple','1','2'],['banana','2','3'],['cherry', '3','4'],['downypitch', '4','5'] ]
newList = wholeList[:]
for e in newList:
    for i, x in enumerate(e):
        try:
            e[i] = int(e[i])
        except ValueError:
            pass
print(newList)

Output:

[['apple', 1, 2], ['banana', 2, 3], ['cherry', 3, 4], ['downypitch', 4, 5]]

Answer 3

If you have mixture of text and number, this would be the best solution

Because string can appear at any location

wholeList = [ ['apple','1','2'],['2','banana', '3'],['3','4', 'cherry'],['downypitch', '4','5'] ]
newlist = []
for sublist in wholeList:
   temp = []
   for string in sublist:
       try:
           temp.append(int(string))
       except:
            temp.append(string)
   newlist.append(temp)
print(newlist)
# op: wholeList = [ ['apple','1','2'],['2','banana', '3'],['3','4', 'cherry'],['downypitch', '4','5'] ]