df.astype code example

Example 1: convert a pandas column to int

# convert Series
my_series = pd.to_numeric(my_series)

# convert column "a" of a DataFrame
df["a"] = pd.to_numeric(df["a"])

Example 2: set column datatype pandas

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