how to convert dtype in pandas code example

Example 1: convert pandas column type

# convert all columns of DataFrame
df = df.apply(pd.to_numeric) # convert all columns of DataFrame

# convert just columns "a" and "b"
df[["a", "b"]] = df[["a", "b"]].apply(pd.to_numeric)

Example 2: set column datatype pandas

df = pd.read_csv("weather.tsv", sep="\t",  
                 dtype={'Day': str,'Wind':int64})
df.dtypes