data = """; No   Time   Date  MoistAve  MatTemp  TDRConduct  TDRAve  DeltaCount  tpAve  Moist1  Moist2  Moist3  Moist4  TDR1  TDR2  TDR3  TDR4
1  11:38:17   11.07.2012  11.37  48.20  5.15  88.87  15  344.50  11.84  11.35  11.59  15.25  89.0  89.0  89.0  88.0
2  11:38:18   11.07.2012  11.44  48.20  5.13  88.88  2  346.22  12.08  11.83  -1.00  -1.00  89.0  89.0  -1.0  -1.0
3  11:38:19   11.07.2012  11.10  48.20  4.96  89.00  3  337.84  11.83  11.59  10.62  -1.00  89.0  89.0  89.0  -1.0
4  11:38:19   11.07.2012  11.82  48.20  5.54  88.60  3  355.92  11.10  13.54  12.32  -1.00  89.0  88.0  88.0  -1.0
"""
date_spec = {'FetchTime': [1, 2]}
df = pd.read_csv(StringIO(data), header=0, sep='\\s\\s+', parse_dates=
    date_spec, na_values=['-1.0', '-1.00'])
Efficiently expand lines from pandas DataFrame