python基础学习(三)
laihuamin opened this issue · comments
条件语句
单个:
if 判断条件:
执行语句...
else:
执行语句...
多个:
if 判断条件:
执行语句...
elif 判断条件:
执行语句...
else:
执行语句...
while循环语句
- while
count = 0
while (count < 9):
print 'The count is:', count
count = count + 1
print "Good bye!"
- while else语句
当执行条件为false的时候,在执行else语句
count = 0
while count < 5:
print count, " is less than 5"
count = count + 1
else:
print count, " is not less than 5"
for循环
for可以循环遍历列表或者字符串
for letter in 'Python': # 第一个实例
print '当前字母 :', letter
fruits = ['banana', 'apple', 'mango']
for fruit in fruits: # 第二个实例
print '当前水果 :', fruit
print "Good bye!"
fruits = ['banana', 'apple', 'mango']
for index in range(len(fruits)):
print '当前水果 :', fruits[index]
print "Good bye!"
- for else 语句
for num in range(10,20): # 迭代 10 到 20 之间的数字
for i in range(2,num): # 根据因子迭代
if num%i == 0: # 确定第一个因子
j=num/i # 计算第二个因子
print '%d 等于 %d * %d' % (num,i,j)
break # 跳出当前循环
else: # 循环的 else 部分
print num, '是一个质数'
break
for letter in 'Python': # 第一个实例
if letter == 'h':
break
print '当前字母 :', letter
var = 10 # 第二个实例
while var > 0:
print '当前变量值 :', var
var = var -1
if var == 5: # 当变量 var 等于 5 时退出循环
break
print "Good bye!"
continue
var = 10
while var > 0:
var = var -1
if var == 5 or var == 8:
continue
print '当前值 :', var
print "Good bye!"
pass
for letter in 'Python':
if letter == 'h':
pass
print '这是 pass 块'
print '当前字母 :', letter
print "Good bye!"