helper functions to generate random data

rnd_gen.py

import random
import string
import datetime


def resample(lst, n):
    ''' return a list of length n of randomly chosen elements
    from an input list'''
    inp = list(lst)
    if n <= 0:
        return random.choice(inp)
    out = [random.choice(inp) for _ in xrange(n)]
    return out


def rnd_string(n=8, uppercase=False, mixcase=False, digits=False):
    '''return a string made of n random letters
       and optionally digits'''
    let = string.ascii_lowercase
    if uppercase:
        let = string.ascii_uppercase
    if mixcase:
        let = string.letters
    if digits:
        let += string.digits
    return ''.join(random.sample(let, n))


def rnd_numbers(n=10, range=(0, 10), integer=False):
    '''return a list of n random numbers within a range'''
    low = range[0]
    high = range[1]
    out = [random.uniform(low, high) for _ in xrange(n)]
    if integer:
        return map(int, out)
    else:
        return out


def rnd_times(n=10, seconds=False):
    '''return a list of n random time-stamps converted to
    strings like hh:mm[:ss]'''
    hrs = rnd_numbers(n=n, range=(0, 24), integer=True)
    mns = rnd_numbers(n=n, range=(0, 60), integer=True)
    out = []
    for i in xrange(n):
        out.append("%02d:%02d" % (hrs[i], mns[i]))
    if seconds:
        for i in xrange(n):
            out[i] += ':%02d' % (int(random.uniform(0, 60)))
    return out


def rnd_dates(n=10, startdate='2000-01-01', enddate='2010-12-31',
              sort=False):
    '''return a list of n random dates between start and end dates
    converted to strings like yyyy-mm-dd'''
    ys, ms, ds = map(int, startdate.split('-'))
    ye, me, de = map(int, enddate.split('-'))
    sd = datetime.date(ys, ms, ds)
    ed = datetime.date(ye, me, de)
    subset = random.sample(xrange(abs((sd - ed).days)), n)
    if sort:
        subset.sort()
    days = []
    for d in subset:
        nd = d1 + datetime.timedelta(days=d)
        days.append(nd.strftime('%Y-%m-%d'))
    return days
    

def rnd_names(n=10, male=True, female=True):
    '''return a list of n male and/or female names'''
    # data from http://listofrandomnames.com/
    files = ['dat/names_male.txt', 'dat/names_female.txt']
    def read_file(f):
        fd = open(f, 'r')
        lines = []
        for line in fd:
            if not line.startswith('#'):
                lines.append(line.strip())
        return lines
    names = []
    if male:
        names.extend(read_file(files[0]))
    if female:
        names.extend(read_file(files[1]))
    if n <= 0:
        return random.choice(names)
    if n > len(names): 
        n = len(names)
    return random.sample(names, n)