def lsem ( inlist ) : sd = stdev ( inlist ) n = len ( inlist ) return sd / math . sqrt ( n )
standard deviation using average code python without list
Returns the estimated standard error of the mean ( sx - bar ) of the values in the passed list . sem = stdev / sqrt ( n )
def lsem (inlist):
    """
Returns the estimated standard error of the mean (sx-bar) of the
values in the passed list.  sem = stdev / sqrt(n)

Usage:   lsem(inlist)
"""
    sd = stdev(inlist)
    n = len(inlist)
    return sd/math.sqrt(n)