[Python] Ejemplo escritura en un fichero

def main():

    principal = 1000 # Initial amount
    rate = 0.05 # Interest rate
    numyears = 5 # Number of years
    year = 1
    f = open("C:\\Users\\oscar\\Documents\\out.txt","w") # Open file for writing
    while year <= numyears:
        principal = principal * (1 + rate)
        #print >>f,"%3d %0.2f" % (year,principal) ####python2
        print("%3d %0.2f" % (year,principal),file=f) #python3
        #otra forma:
        #f.write("%3d %0.2f\n" % (year,principal))
        year += 1
    f.close()

if __name__ == '__main__':
    main()