(20) Loop statement

* While loop
# while expression:
Statement (s)

Guess numbers
#!/usr/bin/env python
#-*-Coding:utf-8-*-

Import Random
Number = Random.randint (1,101)
Guess=0
While True:
Num_input=raw_input ("Please input one integer-is-1 to 100:")
Guess +=1 #统计猜的次数

If not Num_input.isdigit ():
print "Please input integer."
elif Int (num_input) <0 or int (num_input) >100:
Print "The number should in 0 to 100."
Else
If number = = Int (num_input):
Print "Ok,you is good. It's only%d and then you success. " %guess
Break #猜对了就跳出循环
Elif Number>int (num_input):
Print "Your number is more than less."
Elif Number<int (num_input):
Print "Your number is bigger"
Else
Print "Something is wrong."

[Email protected]:/var/www/erp-yejian# python test.py
Please input one integer-is-1 to 100:50
Your number is and less.
Please input one integer-is-1 to 100:75
Your number is bigger
Please input one integer-is-1 to 100:65
Your number is bigger
Please input one integer-is-1 to 100:55
Your number is and less.
Please input one integer-is-1 to 100:60
Your number is and less.
Please input one integer-is-1 to 100:63
Your number is and less.
Please input one integer-is-1 to 100:64
Ok,you is good. It's only 7 and then you success.

# Break and Continue
Break: Jump out of the loop
Continue: Skip this cycle into the next loop
Both of these are controlled circulation processes in the loop body

# while ... else ...
When you run to else, the loop body
#!/usr/bin/env python
#-*-Coding:utf-8-*-

Count=0
While count<3:
Print count, "is less than 3"
Count+=1
Else
Print count, "is isn't less than 3"

[Email protected]:/var/www/erp-yejian# python test.py
0 is less than 3
1 is less than 3
2 is less than 3
3 is isn't less than 3

* Powerful for
>>> mystr= "Hello"
>>> for I in MyStr:
... print I,
...
H e l l o
A letter and a letter printed out

>>> mylist=[11, ' good ', 22]
>>> for I in MyList:
... print I,
...
Good 22
Traverse List

>>> mytuple= (1, ' SS ', 2)
>>> for I in Mytuple:
... print I,
...
1 SS 2
Traversing tuples

>>> mydict={' first ': "Good", "second": "Better"}
>>> for I in Mydict.values ():
... print I,
...
Better good
Traverse Dictionary

>>> myset={' good ', ' better '}
>>> for I in MySet:
... print I,
...
Better good
Iterating through the collection

>>> for I in Range (2,8):
... print I,
...
2 3 4 5 6 7
Traverse the list produced by range

>>> [I for I in range (3,9) if i%2==0]
OUT[2]: [4, 6, 8]
Traversal in List parsing

>>> str1
OUT[16]: ' Hello '
>>> str2
OUT[17]: ' World '
>>> for x, y in Zip (str1,str2):
.. print x, y
...
H W
E o
L R
Dll
o D
and the zip function to use

* Iteration
# ITER
>>> MyList
OUT[42]: [' name ', 88]
>>> List_iter=iter (mylist)
>>> while True:
... print list_iter.next ()
...
Name
88
One-to-one output

(20) Loop statement