For all sets in a list, extract the first number only-CodePudding

I have a list that looks like this:

 b = [{'dg_12.942_ch_293','dg_22.38_ca_627'}, 
{'dg_12.651_cd_286','dg_14.293_ce_334'}, 
{'dg_17.42_cr_432','dg_18.064_cm_461','dg_18.85_cn_474','dg_20.975_cf_489'}]

I want to keep only the first number for each item in each set:

 b = [{'12','22'}, 
{'12','14'}, 
{'17','18','18','20'}]

I then want to find the difference between the smallest and the largest number of each set and put it in a list, so in this case I would have:

b = [3,2,3]

CodePudding user response：

Ugly and without any sanity check, but do the work.

import re

# .*? = non-greedy search
SEARCH_NUMBER_REGEX = re.compile(".*?(\d )")

def foo(dataset):
    out = []
    for entries in dataset:
        numbers = []
        for entry in entries:
           # Search for the first number in the str
           n = SEARCH_NUMBER_REGEX.search(entry).group(1)
           n = int(n)
           numbers.append(n)
        
        # Sort the numbers and sustract the last one (largest)
        # by the first one (smallest)
        numbers.sort()
        out.append(numbers[-1] - numbers[0])

    return out

b = [
    {'dg_12.942_ch_293', 'dg_22.38_ca_627'}, 
    {'dg_12.651_cd_286', 'dg_14.293_ce_334'}, 
    {'dg_17.42_cr_432', 'dg_18.064_cm_461', 'dg_18.85_cn_474', 'dg_20.975_cf_489'}
]

print(b)
# > [10, 2, 3]

CodePudding user response：

This is giving o/p as [10,2,3] (The difference b/w 22 and 12 is 10)

 b = [{'12','22'}, 
{'12','14'}, 
{'17','18','18','20'}] 
l = []
for i in b:
    large ,small = -99, 99
    for j in i:
        j = int(j)
        if large < j:
            large = j
        if small >j:
            small = j
    l.append(large - small)
print(l)

CodePudding user response：

Here's yet another way to do it:

import re

ba = [{'dg_12.942_ch_293', 'dg_22.38_ca_627'},
     {'dg_12.651_cd_286', 'dg_14.293_ce_334'},
     {'dg_17.42_cr_432', 'dg_18.064_cm_461', 'dg_18.85_cn_474', 'dg_20.975_cf_489'}]

bb = []

for s in ba:
    ns = sorted([int(re.search(r'(\d )', ss)[0]) for ss in s])
    bb.append(ns[-1]-ns[0])

print(bb)

Output:

[10, 2, 3]

Or, if you want to be ridiculous:

ba = [{'dg_12.942_ch_293', 'dg_22.38_ca_627'},
     {'dg_12.651_cd_286', 'dg_14.293_ce_334'},
     {'dg_17.42_cr_432', 'dg_18.064_cm_461', 'dg_18.85_cn_474', 'dg_20.975_cf_489'}]

bb = [(n := sorted([int(re.search(r'(\d )', ss)[0]) for ss in s]))[-1]-n[0] for s in ba]

print(bb)

CodePudding user response：

In your final product I see it was "[3,2,3]" but if I am understanding your question correct, it would be [10,2,3]. Either way the code I have below will atleast point you in the right direction (hopefully).

This code will iterate through each tuple in the list and split the str (since that is all we want to compare) and add them into lists. These numbers are then evaluated and subtracts the smallest number from the biggest number, and places it in a separate array. This "separate array" is the final one as shown in your question.

Goodluck - hopefully this helps!

import re

b = [('dg_12.942_ch_293','dg_22.38_ca_627'), ('dg_12.651_cd_286','dg_14.293_ce_334'), ('dg_17.42_cr_432','dg_18.064_cm_461','dg_18.85_cn_474','dg_20.975_cf_489')]

final_array = []

for tup in b:
    x = tup
    temp_array = []
    for num in x: 
        split_number = re.search(r'\d ', num).group()
        temp_array.append(split_number)
    
    difference = int(max(temp_array)) - int(min(temp_array))
    final_array.append(difference)

print(final_array)