填充DataFrame Pandas Python

Question

I have a similar dataset, and even though the code gives me the right output; I do not want to use three for loops. Is there a way to do this in a better way?

import pandas as pd

col = ["a","b","c","d"]
index = ["0","1","2","3"]
dict_ = {("0","a"):8,
         ("1","a"):3,
         ("3","b"):2}

df = pd.DataFrame(columns=col,index=index)
for i in range(len(dict_)):
    for j in range(len(df)):
        for k in range(len(df)):
            if (str(df.index[j]),str(df.columns[k])) == dict_.keys()[i]:
                df.at[df.index[j],df.columns[k]] = dict_.values()[i]

print df

Answer 1

IIUC, using reindex

pd.Series(dict_).unstack().reindex(index=index,columns=col)
Out[245]: 
     a    b   c   d
0  8.0  NaN NaN NaN
1  3.0  NaN NaN NaN
2  NaN  NaN NaN NaN
3  NaN  2.0 NaN NaN