{
"metadata": {
"name": "",
"signature": "sha256:831402bdcf6a50366e6a400bf971e09b25983de0ebf01458d42a693aa22990c1"
},
"nbformat": 3,
"nbformat_minor": 0,
"worksheets": [
{
"cells": [
{
"cell_type": "heading",
"level": 1,
"metadata": {},
"source": [
"CHAPTER 15: MISCELLANEOUS FEATURES"
]
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"EXAMPLE ON PAGE:473-474"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
" \n",
"def emp_dept(*sequential, **named): #definition of enumeration\n",
" enums = dict(zip(sequential, range(len(sequential))), **named)\n",
" return type('Enum', (), enums)\n",
"class employee(): #structure\n",
" def __init__(self,**kwds):\n",
" self.__dict__.update(kwds)\n",
"department=emp_dept('assembly','manufacturing','accounts','stores') #defining a variable of type enum emp_dept\n",
"e=employee(name=\"Lothar Mattheus\",age=28,bs=5575.50,department=department.manufacturing)\n",
"print \"Name=%s\\n\" % (e.name)\n",
"print \"Age=%d\\n\" % (e.age)\n",
"print \"Basic salary=%f\\n\" % (e.bs)\n",
"print \"Dept=%d\\n\" % (e.department)\n",
"if e.department==department.accounts:\n",
" print \"%s is an accountant\\n\" % (e.name)\n",
"else:\n",
" print \"%s is not an accountant\\n\" % (e.name)"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Name=Lothar Mattheus\n",
"\n",
"Age=28\n",
"\n",
"Basic salary=5575.500000\n",
"\n",
"Dept=1\n",
"\n",
"Lothar Mattheus is not an accountant\n",
"\n"
]
}
],
"prompt_number": 1
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"EXAMPLE ON PAGE:475"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
" \n",
"def ASSEMBLY():\n",
" return 0\n",
"def MANUFACTURING():\n",
" return 1\n",
"def ACCOUNTS():\n",
" return 2\n",
"def STORES():\n",
" return 3\n",
"class employee():\n",
" def __init__(self,**kwds):\n",
" self.__dict__.update(kwds)\n",
"e=employee()\n",
"e.name=\"Lothar Mattheus\"\n",
"e.age=28\n",
"e.bs=5575.50\n",
"e.department=MANUFACTURING()\n",
"print \"Name=%s\\n\" % (e.name)\n",
"print \"Age=%d\\n\" % (e.age)\n",
"print \"Basic salary=%f\\n\" % (e.bs)\n",
"print \"Dept=%d\\n\" % (e.department)"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Name=Lothar Mattheus\n",
"\n",
"Age=28\n",
"\n",
"Basic salary=5575.500000\n",
"\n",
"Dept=1\n",
"\n"
]
}
],
"prompt_number": 2
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"EXAMPLE ON PAGE:477-478"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
" \n",
"x=6\n",
"y=4\n",
"a=x/y #int\n",
"print \"Value of a=%f\\n\" % (a)"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Value of a=1.000000\n",
"\n"
]
}
],
"prompt_number": 3
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"EXAMPLE ON PAGE:478"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
" \n",
"x=6\n",
"y=4\n",
"a=float(x)/y #float\n",
"print \"Value of a=%f\\n\" % (a)"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Value of a=1.500000\n",
"\n"
]
}
],
"prompt_number": 4
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"EXAMPLE ON PAGE:478-479"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
" \n",
"a=6.35\n",
"print \"Value of a on type casting=%d\\n\" % (int(a)) #converts float to int\n",
"print \"Value of a=%f\\n\" % (a) "
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Value of a on type casting=6\n",
"\n",
"Value of a=6.350000\n",
"\n"
]
}
],
"prompt_number": 5
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"EXAMPLE ON PAGE:480"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
" \n",
"from ctypes import *\n",
"def MALE():\n",
" return 0\n",
"def FEMALE():\n",
" return 1\n",
"def SINGLE():\n",
" return 0\n",
"def MARRIED():\n",
" return 1\n",
"def DIVORCED():\n",
" return 2\n",
"def WIDOWED():\n",
" return 3\n",
"class employee(Structure):\n",
" _fields_= [(\"gender\",c_short, 1), #1 bit size for storage\n",
" (\"mar_stat\", c_short, 2), #2 bit size for storage\n",
" (\"hobby\",c_short, 3), #3 bit size for storage\n",
" (\"scheme\",c_short, 4)] #4 bit size for storage\n",
"e=employee()\n",
"e.gender=MALE()\n",
"e.mar_status=DIVORCED()\n",
"e.hobby=5\n",
"e.scheme=9\n",
"print \"Gender=%d\\n\" % (e.gender)\n",
"print \"Marital status=%d\\n\" % (e.mar_status)\n",
"import ctypes\n",
"print \"Bytes occupied by e=%d\\n\" % (ctypes.sizeof(e))"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Gender=0\n",
"\n",
"Marital status=2\n",
"\n",
"Bytes occupied by e=2\n",
"\n"
]
}
],
"prompt_number": 6
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"EXAMPLE ON PAGE:481"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
" \n",
"def display():\n",
" print \"Long live viruses!!\\n\"\n",
"print \"Address of function display is %s\\n\" % (display)\n",
"display()"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Address of function display is <function display at 0x02D93DF0>\n",
"\n",
"Long live viruses!!\n",
"\n"
]
}
],
"prompt_number": 7
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"EXAMPLE ON PAGE:481-482"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
" \n",
"def display():\n",
" print \"\\nLong live viruses!!\"\n",
"func_ptr=display\n",
"print \"Address of function display is %s\\n\" % (display)\n",
"func_ptr()"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Address of function display is <function display at 0x05696730>\n",
"\n",
"\n",
"Long live viruses!!\n"
]
}
],
"prompt_number": 8
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"EXAMPLE ON PAGE:483"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
" \n",
"def fun():\n",
" i=20\n",
" return (id(i))\n",
"p=fun\n",
"p()"
],
"language": "python",
"metadata": {},
"outputs": [
{
"metadata": {},
"output_type": "pyout",
"prompt_number": 9,
"text": [
"20688356"
]
}
],
"prompt_number": 9
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"EXAMPLE ON PAGE:483-484"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
" \n",
"def copy(t,s):\n",
" t=\"\\0\"\n",
" for item in s:\n",
" t=t+item\n",
" return t\n",
"source=\"Jaded\"\n",
"target=[]\n",
"str1=copy(target,source)\n",
"print \"%s\\n\" % (str1)"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"\u0000Jaded\n",
"\n"
]
}
],
"prompt_number": 18
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"EXAMPLE ON PAGE:485"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
" \n",
"def findmax(tot_num,*num): #tuples\n",
" max=0\n",
" for count in range(0,len(num),1):\n",
" if num[count]>max:\n",
" max=num[count]\n",
" return max\n",
"max=findmax(5,23,15,1,92,50)\n",
"print \"maximum=%d\\n\" % (max)\n",
"max=findmax(3,100,300,29)\n",
"print \"maximum=%d\\n\" % (max)"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"maximum=92\n",
"\n",
"maximum=300\n",
"\n"
]
}
],
"prompt_number": 19
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"EXAMPLE ON PAGE:486-487"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
" \n",
"def display(type,num,*t):\n",
" def integer():\n",
" for j in range(0,num,1):\n",
" print \"%d\" % (t[j])\n",
" def char():\n",
" for j in range(0,num,1):\n",
" print \"%c\" % (t[j])\n",
" def floating():\n",
" for j in range(0,num,1):\n",
" print \"%f\" % (t[j])\n",
" def switch(ch):\n",
" return {1: integer,\n",
" 2: char,\n",
" 3: floating,\n",
" }[ch]()\n",
" switch(type)\n",
"display(1,2,5,6)\n",
"display(2,4,'A','a','b','c')\n",
"display(3,3,2.5,299.3,-1.0)"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"5\n",
"6\n",
"A\n",
"a\n",
"b\n",
"c\n",
"2.500000\n",
"299.300000\n",
"-1.000000\n"
]
}
],
"prompt_number": 21
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"EXAMPLE ON PAGE:488"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
" \n",
"from ctypes import *\n",
"class a(Union): #definition of union\n",
" _fields_= [(\"i\", c_short),\n",
" (\"ch\",c_byte*2)]\n",
"key=a()\n",
"key.i=512\n",
"print key.i\n",
"print key.ch[0]\n",
"print key.ch[1]"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"512\n",
"0\n",
"2\n"
]
}
],
"prompt_number": 22
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"EXAMPLE ON PAGE:491"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
" \n",
"from ctypes import *\n",
"class a(Union):\n",
" _fields_= [(\"i\", c_short),\n",
" (\"ch\",c_byte*2)]\n",
"key=a()\n",
"key.i=512\n",
"print key.i\n",
"print key.ch[0]\n",
"print key.ch[1]\n",
"key.ch[0]=50\n",
"print key.i\n",
"print key.ch[0]\n",
"print key.ch[1]"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"512\n",
"0\n",
"2\n",
"562\n",
"50\n",
"2\n"
]
}
],
"prompt_number": 1
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"EXAMPLE ON PAGE:492-493"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
" \n",
"from ctypes import *\n",
"class a(Structure):\n",
" _fields_ = [(\"i\", c_short),\n",
" (\"c\", c_byte*2)]\n",
"\n",
"class b(Structure):\n",
" _fields_ = [(\"j\", c_short),\n",
" (\"d\", c_byte*2)]\n",
"\n",
"class z(Union):\n",
" _fields_ = [(\"key\", a),\n",
" (\"data\", b)]\n",
"strange = z()\n",
"strange.key.i=512\n",
"strange.data.d[0]=0\n",
"strange.data.d[1]=32\n",
"print strange.key.i\n",
"print strange.data.j\n",
"print strange.key.c[0]\n",
"print strange.data.d[0]\n",
"print strange.key.c[1]\n",
"print strange.data.d[1]"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"512\n",
"512\n",
"0\n",
"0\n",
"32\n",
"32\n"
]
}
],
"prompt_number": 2
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"EXAMPLE ON PAGE:494-495"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
" \n",
"from ctypes import *\n",
"class info1(Structure):\n",
" _fields_ = [(\"hobby\", c_byte*10),\n",
" (\"crcardno\", c_short)]\n",
"\n",
"class info2(Structure):\n",
" _fields_ = [(\"vehno\", c_byte*10),\n",
" (\"dist\", c_short)]\n",
"\n",
"class info(Union):\n",
" _fields_ = [(\"a\", info1),\n",
" (\"b\", info2)]\n",
"class emp(Structure):\n",
" _fields_ = [(\"n\", c_byte*20),\n",
" (\"grade\", c_byte*4),\n",
" (\"age\", c_short),\n",
" (\"f\", info)]\n",
"e=emp()"
],
"language": "python",
"metadata": {},
"outputs": [],
"prompt_number": 3
}
],
"metadata": {}
}
]
}