def demo():
    """demo is used to demonstrate typical examples about this class."""
    demostr = """
import clubear as cb
#clubear.csv is generated by cb.manager.demo()
pm=cb.pump('clubear.csv') #start a new pump
pm.keep #check the head lists
cb.check(pm).stats() #check the for stats
pm.qlist=['age','height','weight','price','logsales']
cb.check(pm).stats(niter=20,keep=['price']) 
cb.check(pm).corr() #check for correlation
cb.check(pm).table(tv=True) #check table
pm.subsize=10000 #check the subsize
df=pm.go #start to pump data
"""
    print(demostr)
