(input_file,l_max)
return sequences
1.按行读取数据
	2.按l_max分割每条数据,如果长度小于lmax则忽略不计
1.按行读取数据
	2.按l_max分割每条数据,如果长度小于lmax则忽略不计
1 . 按行读取数据 2 . 按l_max分割每条数据 如果长度小于lmax则忽略不计
def Read_Truncate_Data(input_file,l_max):
	'''
	1.按行读取数据
	2.按l_max分割每条数据,如果长度小于lmax则忽略不计
	'''
	f = open(input_file,'r')
	lines = f.readlines()
	sequences = []
	countline = 0
	for line in lines:
		if line.startswith('>'):
			pass
		else:
			countline = countline + 1
			string = line.strip()
			for i in xrange(0,len(string),l_max):
					#print string[i:i+l_max]
				if len(string[i:i+l_max].strip() )== l_max:
					sequences.append(string[i:i+l_max].strip())
	#print len(sequences)
	return sequences
def Read_Truncate_Data ( input_file , l_max ) : f = open ( input_file , 'r' ) lines = f . readlines ( ) sequences = [ ] countline = 0 for line in lines : if line . startswith ( '>' ) : pass else : countline = countline + 1 string = line . strip ( ) for i in xrange ( 0 , len ( string ) , l_max ) : #print string[i:i+l_max] if len ( string [ i : i + l_max ] . strip ( ) ) == l_max : sequences . append ( string [ i : i + l_max ] . strip ( ) ) #print len(sequences) return sequences