Python1：if / while / for...in / break /continue

1.使用if语句

#if.py
number = 23;
guess = int(raw_input('Enter an integer:'));

if guess == number:
    print 'congratulations, u guessed it';
    print 'but u dont win any prize';
elif guess < number:
    print 'no,it is a little heigher than that';
else:
    print 'no,it is a little lower than that';

print 'Done';

2.使用while语句

#while.py
number = 23;
running = 1;
while running:
    guess = int(raw_input('Enter an integer:'));
    if guess == number:
        print 'congratulations, u guessed it';
        running = 0;
    elif guess < number:
        print 'terribly,it is a little lower than that';
    else:
        print 'terribly,it is a little heigher than that';
else:
    print 'that while loop is over';
print 'Done';

3.使用for...in语句

#for.py
for i in range(1,5):
    print i;
else:
    print 'the for loop is over';

4.使用break语句

#break.py
while True:
    s = raw_input('Enter something:');
    if s == 'quit':
        break;
    print 'Length of the string is : ' , len(s);
print 'Done';

5.使用Continue语句

continue语句用来告诉Python条股当前循环块中的剩余语句，然后继续执行下一轮循环。

#break.py
while True:
    s = raw_input('Enter something:');
    if s == 'quit':
        break;
    if len(s) < 3:
        continue;
    print 'Input is of sufficient length';