Question

#Python

I have a dataframe: df = pd.DataFrame({'A':[0,0,15,0,0,12,0,0,0,5]})

And I want to replace the 0 value with the nearest non zero value,

For example, the first value is 0, then I find the the nearest non-zero value is 15, so I replace it as 15, then the data becomes:[15,0,15,0,0,12,0,0,0,5],

Then for all the value except first one, I need to find the both side of the nearest non-zero value, and average them. So for the second 0, it would be (15+15)/2; And the third zero would be (15+12)/2

Answer 1

for i in range(len(df['A'])):
    if df['A'][i]!=0:#comment these 2 lines if average is needed for all the elements, and not just the zero ones
        continue
    if i==0:#for first element
        for r in df['A']:#iterate through all elements in column A, left to right
            if r!=0:#if a non zero element is found
                df['A'][i]=r#assign its value to the first element
                break
    elif i==len(df['A'])-1:#for last element
        for l in df['A'][-2::-1]:#iterate column A, second last element to the first
            if l!=0:#if a non zero element is found
                df['A'][i]=l#assign it to the last element
                break
    else:#for all the other elements
        left=0#variable to hold 1st non zero value on the left side of the current index
        right=0#variable to hold 1st non zero value on the right side of the current index
        for j in range(i+1,len(df['A'])):#iterate from index next to current, up to the end, left to right
            if df['A'][j]!=0:#if we find a non zero element
                right=df['A'][j]#assign the value to right
                break
        for k in range(i-1,-1,-1):#iterate from index one less than current, up to the first, right to left
            if df['A'][k]!=0:#if we find a non zero element
                left=df['A'][k]#assign the value to left
                break
        if left==0:#if left is 0
            df['A'][i]=right#assign right to current index
        elif right==0:#if right is zero
            df['A'][i]=left#assign left to current index
        else:
            df['A'][i]=float(left+right)/2#else, assign average

In [2]: 1 df - pd. DataFrame({'A':[0,0,15,0,0,12,0,0,0,5)}) In [3]: 1 df=df.astype (float) #changing data type to float. to store decimal. Ignore if not needed In [4]: a tn bts лh ta y pop on | for i in range (len (df['A'])): if df['A'][i]!=0: #comment these 2 lines if average is needed for all the elements, and not just the zero ones continue if 10:#for first element for r in df('A']:#iterate through all elements in column A, left to right if r!=0:#if a non zero element is found df['A'][i]=rtassign its value to the first element break elif i=len (df('A'])-1:#for last element for l in df['A'][-2::-1]:iterate column A, second last element to the first if 11-0: #if a non zero element is found df['A') [1] -1 #assign it to the last element break else: #for all the other elements left=0#variable to hold 1st non zero value on the left side of the current index right=0#variable to hold ist non zero value on the right side of the current index for j in range (i+1, len(df['A'])): #iterate from index next to current, up to the end, left to right if df('A'][j]!=0: #if we find a non zero element right-df['A'][j] #assign the value to right break for k in range (i-1,-1,-1): #iterate from index one less than current, up to the first, right to left if df['A'][k] !=0: #if we find a non zero element left-df['A'][k] #assign the value to left break if left=0: #if left is o df['A'][i]=right fassign right to current index elif right--0: #if right is zero df('A') [1]=left#assign left to current index else: df['A'][i]=float(left+right)/2#else, assign average о р у н oo on ју л ь

In [5]: df.iloc[:,0] Out[5] : 0 15.000 1 15.000 15.000 13.500 12.750 12.000 8.500 6.750 5.875 5.000 Name: A, dtype: float64 JUWN