Python strtok equvialent

C programmers usually use strtok to perform operation on string with standing patterns. In Python, we can use re.split to get similar result.

Example:

>>> import re
>>> st = "9394 811 813 815"
>>> result = [str(x) for x in filter(None, re.split('[ ,\n,\t]',st))]
>>> print result
['9394', '811', '813', '815']
>>>

Python read binary file

To read binary file,

fp = open(ifile,"rb")

To read 1 byte from fp,

byte = fp.read(1)

To read 30 bytes from fp,

block = fp.read(30)

block = fp.read(30)

To read the bytes from a block of binary data,

(Year,) = struct.unpack('b',block[3:4])
(Month,) = struct.unpack('b',block[4:5])
(Day,) = struct.unpack('b',block[5:6])
(Hour,) = struct.unpack('b',block[6:7])
(Minute,) = struct.unpack('b',block[7:8])
(Second,) = struct.unpack('b',block[8:9])
recdate = str(Year) + '-' + str(Month) + '-' + str(Day) + ' ' + str(Hour) + ':' + str(Minute)

You should include "import struct" so that you can use the struct module.

To read text from binary data:

(Cellname,) = struct.unpack('8s',blk[2:10])

The format characters are repeated here for quick reference.

Format	C Type	Python type	Standard size	Notes
x	pad byte	no value
c	char	string of length 1	1
b	signed char	integer	1	(3)
B	unsigned char	integer	1	(3)
?	_Bool	bool	1	(1)
h	short	integer	2	(3)
H	unsigned short	integer	2	(3)
i	int	integer	4	(3)
I	unsigned int	integer	4	(3)
l	long	integer	4	(3)
L	unsigned long	integer	4	(3)
q	long long	integer	8	(2), (3)
Q	unsigned long long	integer	8	(2), (3)
f	float	float	4	(4)
d	double	float	8	(4)
s	char[]	string
p	char[]	string
P	void *	integer		(5), (3)

More info of using struct can be found here:
http://docs.python.org/library/struct.html

Python Bitwise Operators:

Bitwise operator works on bits and perform bit by bit operation.
Assume if a = 60; and b = 13; Now in binary format they will be as follows:
a = 0011 1100
b = 0000 1101
-----------------
a&b = 0000 1100

a|b = 0011 1101
a^b = 0011 0001
~a  = 1100 0011
There are following Bitwise operators supported by Python language

Operator	Description	Example
&	Binary AND Operator copies a bit to the result if it exists in both operands.	(a & b) will give 12 which is 0000 1100
|	Binary OR Operator copies a bit if it exists in eather operand.	(a | b) will give 61 which is 0011 1101
^	Binary XOR Operator copies the bit if it is set in one operand but not both.	(a ^ b) will give 49 which is 0011 0001
~	Binary Ones Complement Operator is unary and has the efect of 'flipping' bits.	(~a ) will give -60 which is 1100 0011
<<	Binary Left Shift Operator. The left operands value is moved left by the number of bits specified by the right operand.	a << 2 will give 240 which is 1111 0000
>>	Binary Right Shift Operator. The left operands value is moved right by the number of bits specified by the right operand.	a >> 2 will give 15 which is 0000 1111