my3rd.py

# Column names and column indices to read
#columns = {'date': 0, 'time': 1, 'tempout': 3}
columns = {'date': 0, 'time': 1, 'tempout': 2, 'windspeed': 7}

# Data types for each column (only if non-string)
types = {'tempout': float, 'windspeed': float}

# Initialize my data variable
data = {}
for column in columns:
   data[column] = []

# Read and parse the data file
filename = "data/wxobs20170821.txt"
with open(filename, 'r') as datafile:

   # Read the first three lines (header)
   for _ in range(3):
      datafile.readline()

   # Read and parse the rest of the file
   for line in datafile:
      split_line = line.split()
      for column in columns:
         i = columns[column]
         t = types.get(column, str)
         value = t(split_line[i])
         data[column].append(value)

# DEBUG
print(data['tempout'])