The viscosity μμ of gases depends on the temperature TT . For some gases the following formula is relevant:

μ(T)=μ0T0−CT+C(TT0)1.5,μ(T)=μ0T0−CT +C(TT0)1.5,

where the values of the constants CC , T0T0 , and μ0μ0 are found in a file viscosity. dat. The temperature is measured in Kelvin.

Suppose we have already loaded the file into a string viscosity_data using the read method. viscosity_data contains data (in order as gas, C,T_0,mu_0) such as:

viscosity_data = '''air,120,291.15,18.27
nitrogen,111,300.55,17.81
oxygen,127,292.25,20.18
carbon dioxide,240,293.15,14.8
carbon monoxide,118,288.15,17.2
hydrogen,72,293.85,8.76
ammonia,370,293.15,9.82
sulphur dioxide,416,293.65,12.54'''
Convert the data in the string viscosity_data into a nested dictionary mu_data such that we can look up CC , T0T0 , and μ0μ0 for a gas with a name name by mu_data[name][X], where X can be one of 'C', 'T_0', or 'mu_0'. The numerical values in mu_data should all be floats.

For instance, the following statements should be True:

mu_data[ 'air' ][ 'C' ] == 120.0
mu_data[ 'hydrogen' ][ 'T_0' ] == 293.85
mu_data[ 'sulphur dioxide' ][ 'mu_0' ] == 12.54