Python conditions, loops, termination

1. Indent

Python uses the TAB key to differentiate the logic of the Code, that is, indentation, which is equal to four spaces in one indent

2.if conditions

Format:

If judging condition:

EXECUTE statement ...

Elif:

Execute statement ...

else:

Execute statement ...

Example:

A = Ten

B = -

if a>b:

Print("a>b")

elif a<b:

Print("a<b")

Else :

Print("a=b")

3.while Cycle

Format:

While judging condition:

EXECUTE statement ...

Example:

A = 3

while a> 0 :

Print("1111")

a-= 1

4.for Cycle

Format:

For Iterating_var in sequence:

Statements (s)

Example:

list1= [] Span style= "Font-size:12px;font-family:simsun, Stsong;color:rgb (0,0,255); Background-color:rgb (255,255,255);" >1 Span style= "Font-size:12px;font-family:simsun, Stsong;color:rgb (0,0,255); Background-color:rgb (255,255,255);" >3 Span style= "Font-size:12px;font-family:simsun, Stsong;color:rgb (0,0,255); Background-color:rgb (255,255,255);" >4 Span style= "Font-size:12px;font-family:simsun, Stsong;color:rgb (0,0,255); Background-color:rgb (255,255,255);" >2 "

for a inch List1:

Print(a)

Common methods:

1) Enumerate: subscript and corresponding value

Example:

Dict1 =Dict(a=1,b=2,C=3,D=4)

for key1, value1 in Enumerate ( DICT1):

Print(key1,value1)

2) print (range (1,10)): Print all at once 1-10 (memory)

Example:

Print (range(1,ten))

3) Print (xrange (1,10)): Print 1-10 on call

Example:

forIinchxrange(1,Ten):

Print (i)

Example:

xrange ( 1 10

Print (i)

Print List (i)

5.break and Continue termination

1) Continue: Jumps to the beginning of the next cycle

Example:

forIinchxrange(1,6):

If i = = 3:

Continue

Print ("i=%d" % i)

2) Break: Jump out of the loop

Example:

forIinchxrange(1,6):

If i = = 3:

break

Print ("i=%d" % i)

Python conditions, loops, termination