"""
python核心编程练习2
使用的python版本: Python 3.2.3
"""
def t2_5():
"""分别写一个while和for循环，输出整数0～10。
"""
i = 0
while i <= 10:
print(i,'', end='')
i += 1
print()
for i in range(0, 11):
print(i,'', end='')
print()
def t2_6():
"""条件判断。
判断一个数是整数，负数，或者等于0.
"""
try:
anum = int(input('Enter a number: '))
except ValueError:
print('what you entered is not a number!!!')
else:
print(anum)
def t2_7():
"""输入一个字符串，逐个字符输出该字符串。使用while和for
"""
astr = input('Enter a string: ')
for eachar in astr: print(eachar, end='')
print()
strlen = len(astr)
i = 0
while i < strlen:
print(astr[i], end='')
i += 1
print()
def t2_8():
"""输入5个数，分别存入list和tuple，算出他们的和
"""
alist = []
atuple = ()
for i in range(0, 5):
num = int(input('Enter a number: '))
alist.append(num)
atuple = atuple + (num, )
total = 0
for num in alist:
total += num
print(total)
total = 0
for num in atuple:
total += int(num)
print(total)
def t2_9():
"""输入5个数，存入list和tuple，算出他们的平均值
在python3.2版本中，单除号/实现的是小数除法，可以直接用，不过这里考虑
输入的数可能为浮点数，所以也用float对输入进行转换
如果在2.x版本中，如果输入的是整数，需要先将数转成float，再除
"""
alist = []
atuple = ()
# input 5 numbers
for i in range(0, 5):
num = float(input('Enter a number: '))
alist.append(num)
atuple = atuple + (num, ) # 向一个tuple添加元素，要使用tuple相加
# 所以这里先办单个数num组成一个只有一个
# 元素的tuple再与原来的tuple相加
total = 0
for num in alist:
total += num
print(total/len(alist))
total = 0
for num in atuple:
total += num
print(total/len(atuple))
def t2_10():
"""让用户输入一个1～100之间的数，如果用户输入的数满足条件，
显示成功并推出，否则显示错误信息，然后再次提示用户输入。
"""
prompt = 'Please input a number (1~100): '
while True:
try:
num = int(input(prompt))
except ValueError:
print('Not a number')
else:
if 1 <= num <= 100:
break
else:
print(num, 'not correct')
print('Yes, you got it.')
def t2_11():
"""带文本菜单的程序。
菜单如下(1)取5个数的和 （2）取5个数的平均值 （X）退出
"""
prompts = '''
(1)sum of five numbers.
(2)average of five numbers.
(X)Quit
Enter your choice: '''
while True:
choice = input(prompts).strip()[0].lower()
print('\nYou picked [{}]'.format(choice))
if choice not in '12x':
print('Invalid options:', choice)
elif choice == '1':
t2_8()
elif choice == '2':
t2_9()
else:
break
def t2_15():
"""用户输入三个数，保存至不同的变量中。不使用列表或排序算法，
自己写代码来对这三个数进行排序：从大到小，从小到大
"""
aa = int(input('Enter a number: '))
bb = int(input('Enter a number: '))
cc = int(input('Enter a number: '))
a, b, c = aa, bb, cc
# from smallest to largest
if a > b:
a, b = b, a # swap two value
if a > c:
a, c = c, a
if b > c:
b, c = c, b
print('{} < {} < {}'.format(a, b, c))
# from largest to smallest
a, b, c = aa, bb, cc
if a < b:
a, b = b, a
if a < c:
a, c = c, a
if b < c:
b, c = c, b
print('{} > {} > {}'.format(a, b, c))
def t2_16():
"""输入一个文件名，然后读取该文件，并将文件内容输入到屏幕上
"""
filename = input('Enter file name: ')
fobj = open(filename, 'r')
for eachline in fobj:
print(eachline, end='') # 默认的print语句会加换行，这里把换行去掉
fobj.close()
if __name__ == '__main__':
#t2_5()
#t2_6()
#t2_7()
#t2_8()
#t2_9()
#t2_10()
#t2_11()
#t2_15()
#t2_16()