cast column pandas code example

Example 1: change dataframe column type

>>> df.astype({'col1': 'int32'}).dtypes
col1    int32
col2    int64
dtype: object

Example 2: pandas change to numeric

>>> s = pd.Series(["8", 6, "7.5", 3, "0.9"]) # mixed string and numeric values
>>> s
0      8
1      6
2    7.5
3      3
4    0.9
dtype: object

>>> pd.to_numeric(s) # convert everything to float values
0    8.0
1    6.0
2    7.5
3    3.0
4    0.9
dtype: float64

Example 3: 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 4: set column datatype pandas

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