Python重写C语言程序100例--Part6

时间:2023-03-09 15:02:07
Python重写C语言程序100例--Part6
'''
【程序41】
题目:学习static定义静态变量的使用方法   
1.程序分析:
2.程序源码:
'''
# python没有这个功能了,仅仅能这样了:)
def varfunc():
var = 0
print 'var = %d' % var
var += 1
if __name__ == '__main__':
for i in range(3):
varfunc() # attribut of class
# 作为类的一个属性吧
class Static:
StaticVar = 5
def varfunc(self):
self.StaticVar += 1
print self.StaticVar print Static.StaticVar
a = Static()
for i in range(3):
a.varfunc()
'''
题目:学习使用auto定义变量的使用方法
1.程序分析:      
2.程序源码:
没有autokeyword,使用变量作用域来举例吧
'''
num = 2
def autofunc():
num = 1
print 'internal block num = %d' % num
num += 1
for i in range(3):
print 'The num = %d' % num
num += 1
autofunc()
'''
【程序43】
题目:学习使用static的还有一使用方法。   
1.程序分析:
2.程序源码:
有一个static变量的使用方法,python是没有,演示一个python作用域使用方法
'''
class Num:
nNum = 1
def inc(self):
self.nNum += 1
print 'nNum = %d' % self.nNum if __name__ == '__main__':
nNum = 2
inst = Num()
for i in range(3):
nNum += 1
print 'The num = %d' % nNum
inst.inc()
'''
【程序45】
题目:学习使用register定义变量的方法。
1.程序分析:
2.程序源码:
没有registerkeyword,用整型变量取代
'''
tmp = 0
for i in range(1,101):
tmp += i
print 'The sum is %d' % tmp
'''
【程序46】
题目:宏#define命令练习(1)   
1.程序分析:
2.程序源码:
没有C语言的宏,就这么写了
'''
TRUE = 1
FALSE = 0
def SQ(x):
return x * x
print 'Program will stop if input value less than 50.'
again = 1
while again:
num = int(raw_input('Please input number'))
print 'The square for this number is %d' % (SQ(num))
if num >= 50:
again = TRUE
else:
again = FALSE
'''
题目:宏#define命令练习(2)
1.程序分析:            
2.程序源码:
#include "stdio.h"
#define exchange(a,b) { \ /*宏定义中同意包括两道衣裳命令的情形,此时必须在最右边加上"\"*/
            int t;\
            t=a;\
            a=b;\
            b=t;\
           }'
这个宏定义python不支持
'''
def exchange(a,b):
a,b = b,a
return (a,b) if __name__ == '__main__':
x = 10
y = 20
print 'x = %d,y = %d' % (x,y)
x,y = exchange(x,y)
print 'x = %d,y = %d' % (x,y)
'''
【程序48】
题目:宏#define命令练习(3)   
1.程序分析:
2.程序源码:
#define LAG >
#define SMA <
#define EQ ==
#include "stdio.h"
void main()
{
int i=10;
int j=20;
if(i LAG j)
printf("\40: %d larger than %d \n",i,j);
else if(i EQ j)
printf("\40: %d equal to %d \n",i,j);
else if(i SMA j)
printf("\40:%d smaller than %d \n",i,j);
else
printf("\40: No such value.\n");
}
不知道怎样用python实现相似的功能
'''
if __name__ == '__main__':
i = 10
j = 20
if i > j:
print '%d larger than %d' % (i,j)
elif i == j:
print '%d equal to %d' % (i,j)
elif i < j:
print '%d smaller than %d' % (i,j)
else:
print 'No such value'
'''
【程序49】
题目:#if #ifdef和#ifndef的综合应用。
1. 程序分析:
2.程序源码:
#include "stdio.h"
#define MAX
#define MAXIMUM(x,y) (x>y)?x:y
#define MINIMUM(x,y) (x>y)?y:x
void main()
{
int a=10,b=20;
#ifdef MAX
printf("\40: The larger one is %d\n",MAXIMUM(a,b));
#else
printf("\40: The lower one is %d\n",MINIMUM(a,b));
#endif
#ifndef MIN
printf("\40: The lower one is %d\n",MINIMUM(a,b));
#else
printf("\40: The larger one is %d\n",MAXIMUM(a,b));
#endif
#undef MAX
#ifdef MAX
printf("\40: The larger one is %d\n",MAXIMUM(a,b));
#else
printf("\40: The lower one is %d\n",MINIMUM(a,b));
#endif
#define MIN
#ifndef MIN
printf("\40: The lower one is %d\n",MINIMUM(a,b));
#else
printf("\40: The larger one is %d\n",MAXIMUM(a,b));
#endif
}
这个还是预处理的使用方法,python不支持这种机制,演示lambda的使用。
'''
MAXIMUM = lambda x,y : (x > y) * x + (x < y) * y
MINIMUM = lambda x,y : (x > y) * y + (x < y) * x if __name__ == '__main__':
a = 10
b = 20
print 'The largar one is %d' % MAXIMUM(a,b)
print 'The lower one is %d' % MINIMUM(a,b)

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