如何为列表列表中的特定项目分配标签

Question

I'm working on computing minimum values from a csv row (of which I have turned into a normalised list of list) and am having trouble assigning the original csv title / header with the corresponding minimum value from that row (of which I omitted both to make the normalization easier). Below is what I am working with:

My normalised list of lists (each sublist is a row from my csv file)

[[0.1442722616425349, 0.011387368532690107, 1.0, 0.01016955650916749, 0.0, 0.007007584956949359], [0.13618895033835154, 0.009739033790403672, 1.0, 0.011358919624000634, 0.0, 0.007134183651352274], [0.14773629092116417, 0.015197531681779487, 1.0, 0.009581175298448931, 0.0], [0.1480962502699423, 0.01613878131072959, 1.0, 0.015035304680545728, 0.0, 0.007260689113737381], [0.1404716315950755, 0.012720171642799673, 1.0, 0.011429478548387115, 0.0, 0.005808759430147285], [0.14362441283729363, 0.008943844575022054, 1.0, 0.008400152860935555, 0.0, 0.0020931326050634305]]

I calculate the minimum of each sublist (row) using

min_list = [min(p) for p in norm_row_list]

and obviously the output will be

[0.0, 0.0, 0.0, 0.0, 0.0, 0.0]

But what I want is instead of printing out numbers to print which column that number came from (each column has a string header, eg the first 0.0 is from my second last column [5] called Generosity). As well as print out the title (which is located in the first column, with the first row in that column being Afghanistan).

country,      header2,     header3,     header4,     header5      header6
Australia     1.0          0.3435353    0.0          0.23124234   0.35334
Algeria       0.343434     0.434343     1.0          0.0          0.344343

So I need to the compute the min of each row and have it out below:

Australia's happiness is bound by its header4
Algeria's happiness is bound by its header5

Answer 1

Let headers be column headers and list_of_lists all the other rows (including the country column). Then the following do what you want:

headers = ['country', ...]

for mList in list_of_lists:
  cur_min = 1000
  min_index = 0
  for col_index, item in enumerate(mList[1:]):
    if item < cur_min:
      cur_min = item
      min_index = col_index
  print(mList[0] + "'s happiness is bound by its " + headers[min_index + 1])

If the minimum is always 0, then the above code can be simplified.

Example of the above mentioned variables:

list_of_lists = [['Australia',1.0,0.3435353,0.0,0.23124234,0.35334],['Algeria',0.343434,0.434343,1.0,0.0,0.344343]]
headers = ['country','a','b','c','d','e','f']

Answer 2

If you are OK with using pandas, this can be done pretty easily. First import you CSV into pandas as dataframe with

df=pd.read_csv('filename.csv') #need to look-up other postas which will help you read your CSV into pandas as a dataframe.

Then use the below code.

for index, row in df.iterrows():
    print (row['country,'] + ' happiness is bound by its ' + df.columns[row.values == 0][0])

My input is the data frame as below

    country,    header2,    header3,    header4,    header5
0   Australia   1.000000    0.343535    0.0     0.231242
1   Algeria     0.343434    0.434343    1.0     0.000000

Ouput

Australia happiness is bound by its header4,
Algeria happiness is bound by its header5

Answer 3

I'm not sure if I understand the question fully but this would allow you to read in a CSV and output what you're looking for without having to put it into a list of lists. I avoided things like pandas because it's gibangous and maybe that's overkill. Those libraries are for sure the way to go for more complex work, though.

for a csv similar to this structure

country,header1,header2,header3,header4,header5,header6
Algeria,1,2,55,3,2,3
Australia,33,2,8,3,99,0
UnitedStates,9,8,7,6,5,4

You could use this code

import csv

with open('file.csv', newline="\n") as f:
    reader = csv.DictReader(f)
    for row in reader:
        # do whatever normalization to row values you need to do
        minval = min(([v for i,v in enumerate(row.values()) if i != 0]))
        i = [v for i,v in enumerate(row.values()) if i != 0].index(minval)
        h = [r for r in row.keys()][i+1]
        print(f"{row['country']}'s happiness is bound by its {h}")

If you have to work from a list of lists, you can put the headers into a variable, capture the index of the minimum value with the list.index function and reference the correct header from that index the same way I initialized i in the snippet I pasted.

headers = ['header1', 'header2', ...]
countries = ['a', 'bunch', 'o', 'countries', ...]
for ci,row in enumerate(list_of_lists):
    minval = min(row)
    i = row.index(minval)
    h = headers[i]
    print(f"{countries[ci]}'s happiness is bound by its {h}")

I hope I caught what you were shooting for. Good luck!

Answer 4

I think you mean

header = ['country', 'header2', 'header3', 'header4', 'header5', 'header6']

[header[p.index(min(p))] for p in norm_row_list]

# ['header5', 'header5', 'header5', 'header5', 'header5', 'header5']

Given that norm_row_list you provided above.