[Tutor] Python regular expression

[kumar s]

Dear group, 

I have a file with 645,984 lines.  This file is
composedcompletely of bocks.

For e.g.

[Unit111]
Name=NONE
Direction=2
NumAtoms=16
NumCells=32
UnitNumber=111
UnitType=3
NumberBlocks=1

[Unit111_Block1]
Name=31318_at
BlockNumber=1
NumAtoms=16
NumCells=32
StartPosition=0
StopPosition=15
CellHeader=X	Y	PROBE	FEAT	QUAL	EXPOS	POS	CBASE	PBASE
TBASE	ATOM	INDEX	CODONIND	CODON	REGIONTYPE	REGION
Cell1=24	636	N	control	31318_at	0	13	A	A	A	0	407064	-1
-1	99	
Cell2=24	635	N	control	31318_at	0	13	A	T	A	0	406424	-1
-1	99	
Cell3=631	397	N	control	31318_at	1	13	T	A	T	1	254711
-1	-1	99	



[Unit113]
Name=NONE
Direction=2
NumAtoms=16
NumCells=32
UnitNumber=113
UnitType=3
NumberBlocks=1

[Unit113_Block1]
Name=31320_at
BlockNumber=1
NumAtoms=16
NumCells=32
StartPosition=0
StopPosition=15
CellHeader=X	Y	PROBE	FEAT	QUAL	EXPOS	POS	CBASE	PBASE
TBASE	ATOM	INDEX	CODONIND	CODON	REGIONTYPE	REGION
Cell1=68	63	N	control	31320_at	0	13	T	A	T	0	40388	-1
-1	99	
Cell2=68	64	N	control	31320_at	0	13	T	T	T	0	41028	-1
-1	99	
Cell3=99	194	N	control	31320_at	1	13	C	C	C	1	124259	-1
-1	99	





I have a file with identifiers that are found in the
first file as :
Name=31320_at


I am interested in getting lines of block that are
present in first to be written as a file.  

I am search:

search = re.search ["_at")


my question:
how can i tell python to select some rows that have
particular pattern such as [Name] or Name of [Unit]. 
is there any way of doing this. 
please help me

thanks
kumar

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