fill an empty matrix with random floats

[sofiapuvogel]

Im new in programming and I want to fill just the first column of a matrix with diferent random float within a certain range (low and high limits), but when I run my code it fills all the rows in the first column with the same value. Please help me! :)

import numpy as np
import random
res=np.zeros([5,2])#empty matrix
first_col_res=res[:,0] #the first column of matrix res
seen=set()

def rand_teta(low, high,k):#k refers to the total random numbers:
    
    j=0
    while j <=k:
        x=random.uniform(low,high)
        
        j=j+1
        while x in seen:
            x=random.uniform(low,high)
    seen.add(x)
    first_col_res.fill(x)
    
    return res
#out put example
rand_teta(1,2,3)

Output:
Out[88]: 
array([[1.72762661, 0.        ],
       [1.72762661, 0.        ],
       [1.72762661, 0.        ],
       [1.72762661, 0.        ],
       [1.72762661, 0.        ]])