#!/usr/bin/env python3
#define
s = set([1,2,3])
print(s)
t = set("hello")
print(t)
a = s | t
b = s & t
c = s - t
d = s ^ t
print(a, b, c, d)
t.add('x')
print(t)
s.update([10, 11, 12]) #replace
print(s)
person = {
"name" : "tianxun",
"age" : 26,
"sex" : "man"
}
if "age" in person:
p = person["age"]
else:
p = 0
print(p)
#this if else statement is equal to the follow statement.
p = person.get("sex", "man")
print(p)
syms = list(person)
print(syms)
del person["age"]
print(person)
#----------
a = "hello world"
for i in a:
print(i)
for line in open("file_dir/foo.txt"):
print(line)
#more line write
for line in \
open("file_dir/foo.txt"):
print(line)
def remainder(a,b):
q = a // b
r = a - q * b
return r
print(remainder(73, 10))
