Looping and append to dataframe with column names in Pyhton

Question

I had this challenge of looping through and appending to a data frame in 2 separate columns. I would like the result of col1 and col2 to be appended to the data frame under the columns 'col1' & 'col2'.

What i have so far is the below:

result = pd.DataFrame(columns = ['col1', 'col2'])
for i in range(5):
    col1 = i + 1
    col2 = i + 100
    result.append(pd.concat([str(col1), col2]))

Which outputs:

TypeError: cannot concatenate object of type '<class 'str'>'; only Series and DataFrame objs are valid

My desired output is:

col1	col2
1	101
2	102
3	103
4	104
5	105