isnull in python code example

Example 1: isnumeric python

str.isnumeric()
str = u"this2009";  
print str.isnumeric()
> False
str = u"23443434";
print str.isnumeric()
> True

Example 2: isnull().mean() python

df.isnull()
#Mask all values that are NaN as True
df.isnull().mean()
#compute the mean of Boolean mask (True evaluates as 1 and False as 0)
df.isnull().mean().sort_values(ascending = False)
#sort the resulting series by column names descending