how to remove rows with nan in pandas

import pandas as pd

df = pd.DataFrame({'values_1': ['700','ABC','500','XYZ','1200'],
                   'values_2': ['DDD','150','350','400','5000'] 
                   })

df = df.apply (pd.to_numeric, errors='coerce')
df = df.dropna()
df = df.reset_index(drop=True)

print (df)

x = x[~numpy.isnan(x)]

df.dropna()     #drop all rows that have any NaN values
df.dropna(how='all')