pandas change to numeric

1df['myvar'] = df['myvar'].astype(str)   # Transform as character
2df['myvar'] = df['myvar'].astype(float) # Transform as float
3df['myvar'] = df['myvar'].astype(int)   # Transform as numeric

1>>> s = pd.Series(["8", 6, "7.5", 3, "0.9"]) # mixed string and numeric values
2>>> s
30      8
41      6
52    7.5
63      3
74    0.9
8dtype: object
9
10>>> pd.to_numeric(s) # convert everything to float values
110    8.0
121    6.0
132    7.5
143    3.0
154    0.9
16dtype: float64
17