If, while, for syntax and instances in Python

1.if/while/for

Python indentation:

MAIN:PASSC Main (param) {}java main (param) {}

If judgment:

If judgment condition: Execute statement elif judgment condition: Execute statement else: EXECUTE statement

While loop:

Whle judgment Condition: Execute statement break jump out of the loop continue jump out of the loop and into the next loop

For loop:

For item in sequence: Execute statement for I,J in Enumerate (list1): Print (I,J)

Slice:

L = [' A ', ' B ', ' C ', ' d ', ' E ']print (L[0:5]) # 0 << x < 5for x, y in Enumerate (l): print (x, y) Result: [' A ', ' B ', ' C ', ' d ', ' E '] 0 a 1 B 2 c 3 D 4 E print (l[:]) Take all

2.Python instance

The idea and thought of doing a problem is the most important:

Example 1:

ABCD*9=DCBA a=? B=? C=?   D=? Answer: a=1,b=0,c=8,d=9 1089*9=9801

#!/usr/bin/env python# -*- coding:utf-8 -*-#  @Time:   2018-01-23  16:31#  @Author: feng xiaoqing#  @File:    if-while-for.pyfor a in  range (1,10):     for b in range (0,10):         for c in range (0,10):             for d in range (0,10):                 start = a * 1000 + b * 100  + c * 10 + d                 end = d * 1000 + c * 100 + b  * 10 + a                 if start * 9 == end :                 print  (' {0} * 9 = {1} '. Format (start,end))

Answer:

1089 * 9 = 9801

Example 2:

Ask for factorial 0 of N! + 1! + 2! + 3! ... + n!

#!/usr/bin/env python# -*- coding:utf-8 -*-#  @Time:   2018-01-23  15:31#  @Author: feng xiaoqing#  @File:    if-while-for.pydef one (n):     total = 1    if n == 0:         total = 1    else:         for i in range (1,int (n) +1):         Total *= i    return totalwhile true:    result  = 0    n = input ("Please input a number:")      if  not n.isdigit ()  :        print ("  the number is error! ")         break    for i&nbSp;in range (0,int (n) +1):         result += one (i)          print ("0! + 1! + 2! + 3! ...+  N! = {0} ". Format (Result))

If, while, for syntax and instances in Python