how to make Pandas DataFrame (Python) to display each cell in a two dimensional (2-D) matrix format

Question

I am trying to create a two dimensional (2-D) data structure using a Matlab structure imported in Python.

When I use pandas.DataFrame, each cell contains a matrix, however, they are displayed in the List format. I am trying to change it to the Matrix format.

The DataFrame in Python would look similar using the following code: (However, it is not the same, since the real data is imported from Matlab and would have a different type which I could not recreate it using python)

import pandas as pd
k=[[0,1,2,3,4,5,6]]
df=pd.DataFrame(k)
df[:] = df[:].astype('object')
df.at[0,0] = [[1]]
df.at[0,1] = [[1.0,2.0],[2.0,4.0],[8.0,3.0],[9.0,7.0]]
df.at[0,2] = [[0.487],[1.532],[1.544],[1.846]]
df.at[0,3] = [[3.0]]
df.at[0,4] = [[3.0]]
df.at[0,5] = [[-1]]
df.at[0,6] = [[]]
display(df)

Which results in:

Result_of_the_code

(You can also find similar result by running the following snippet.)


  
    
      
      0
      1
      2
      3
      4
      5
      6
    
  
  
    
      0
      [[1]]
      [[1.0, 2.0], [2.0, 4.0], [8.0, 3.0], [9.0, 7.0]]
      [[0.487], [1.5326], [1.544], [1.846]]
      [[3.0]]
      [[3.0]]
      [[-1]]
      [[]]

As you can see, each cell is displayed as a list, i.e:

Displayed_matrix_as_list_form

(You can also find similar result by running the following snippet.)


    [[1.0, 2.0], [2.0, 4.0], [8.0, 3.0], [9.0, 7.0]]

I am trying to change it to something like:

Intended_result

(You can also find similar result by running the following snippet.)

.matrix {
        position: relative;
    }
    .matrix:before, .matrix:after {
        content: "";
        position: absolute;
        top: 0;
        border: 1px solid #000;
        width: 6px;
        height: 100%;
    }
    .matrix:before {
        left: -10px;
        border-right: -0;
    }
    .matrix:after {
        right: -10px;
        border-left: 0;
    }

Thank you.

Mohammad Badri Ahmadi · Accepted Answer

@Attack68, here is the code I mentioned in reply to your beautiful answer. just remember, as I mentioned, the real data are imported from a Matlab structure. Meaning it would not work with the data I provided in the question itself, but works fine with Matlab structures imported to python using scipy.io. I wrote this code with the help of @Valdi_Bo answer on link and @Paul Panzer answer on link.

df = pd.DataFrame(data)

import re 
def pretty_col(data):
     data=np.array(data)
     if data.size <= 1:
         return format(data)
     else:
         return format(data[:, None])[1:-1].replace('[', '\u23A1', 1).replace(' [', '\u23A2', data.size-2).replace(' [', '\u23A3').replace(']', '\u23A4', 1).replace(']', '\u23A5', data.size-2).replace(']', '\u23A6')
def pretty_cols(data, comma=False):
    if comma:
        f='
'.join(line[0] + line + line[-1] for line in map(str.join, data.shape[0] // 2 * ('  ',) + (', ',) + (data.shape[0] - 1) // 2 * ('  ',), zip(*map(str.split, map(pretty_col, data.T), data.shape[1]*('
',)))))
    else:
        f='
'.join(line[0] + line + line[-1] for line in map(''.join, zip(*map(str.split, map(pretty_col, data.T), data.shape[1]*('
',)))))
    return f

def myFmt(txt):
    if txt=="":
        return "[]"
    else:
        q=r'bananas
'
        q=q.replace("bananas", repr(txt))
        q=q.replace("'", '')
        return q.replace(r'
', '
')
def ttest(x):
    for i,k in enumerate(x):
        for j,l in enumerate(k):
            x[i][j]=float(format(l, '.2f'))
            return x

def transform(tdf,prec):
    for col in tdf.columns:
        tdf[col] = tdf[col].apply(pretty_cols)
        for j in range(len(tdf[col])):
            tdf[col][j]=fixing_newline(tdf[col][j],prec)


print(df[df.columns[0]])
def fixing_newline(string,prec):
    string=string.replace("⎡⎡", ' aa ').replace("⎤⎤", ' bb ').replace("
", ' cc ').replace("⎢⎢", ' dd ').replace("⎥⎥", ' ee ').replace("⎣⎣", ' ff ').replace("⎦⎦", ' gg ').replace("[[", ' hh ').replace("]]", ' kk ')
    chunks = string.split(' ')
    string=""
    for i,k in enumerate(chunks):
        try: 
            string+=str("{:."+str(prec)+"f}").format(float(k))
        except ValueError:
            string+=k
    string=string.replace("aa", "⎡⎡").replace("bb", '⎤⎤').replace("cc", '
').replace("dd", '⎢⎢').replace("ee", '⎥⎥').replace("ff", '⎣⎣').replace("gg", '⎦⎦').replace("hh", '[[').replace("kk", ']]')
    return string


transform(df,3)
df=df.style.format(myFmt)

display(df)

which would result in something like: Results (Need help with inline images since I do not have enough reputation.)

However, the code is not efficient at all, and also does not work well all the time.

how to make Pandas DataFrame (Python) to display each cell in a two dimensional (2-D) matrix format

Answers (2)

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