def load_info(f_name):
"""
loads the header, header_length and number of data columns in a file
arguments:
f_name: <*.csv> (string) the name of the file
return values:
n_cols: (int) the number of columns
h_len: (int) the number of rows in the header
header: (((string) list) list) a list of the list of the strings in
each "cell" of the header
"""
f_stream = open(f_name, "r")
h_len = 0
n_cols = 0
header = []
while True:
line = f_stream.readline()
if line == "" or line == "\n":
break
segs = line.split(',')
try:
csvd.string_to_datetime(segs[0])
break
except (ValueError, AttributeError):
header.append(segs)
h_len += 1
n_cols = len(header[-1])
f_stream.close()
return n_cols, h_len, header
def load_csv_file_opti(self):
"""
a faster load file
"""
for idx in range(self.m_numcols):
self.m_datacols.append([])
f_stream = open(self.m_name, "rb")
f_stream.seek(-2,2)
while f_stream.read(1) != "\n":
f_stream.seek(-2,1)
line = f_stream.readline()
if line.strip() == "":
return
if line[:line.find(',')] == self.m_header[-1][0]:
return
cells = line.split(",")
for col in range(len(cells)):
if col == 0:
self.m_datacols[col].append(csvd.string_to_datetime(cells[col]))
else:
self.m_datacols[col].append(float(cells[col]))
f_stream.close()
#store last date in the file
try:
self.m_last_init_date = self.m_datacols[0][-1]
except IndexError:
pass
def load_file_to_plot(f_name, skip = 4):
"""
loads a array of a datetime.datetime object and an array of
coorisponding values
arguments
f_name: (string)the file name
skip: (int) number of rows to skip (defaluts to 4 the data logger
header length)
"""
date_string , value = numpy.loadtxt(f_name,
dtype = {'names':('date' , 'val'),'formats':('S100','f4')},
delimiter=',', usecols=(0 , 1), skiprows=skip, unpack=True)
date = []
for items in date_string:
date.append(csvd.string_to_datetime(items))
date = numpy.array(date)
return date, value
def load_csv_file(self):
"""
loads a csv file replaces the csv_utitlies version
"""
f_stream = open(self.m_name, "r")
f_text = f_stream.read()
f_stream.close()
rows = f_text.replace("\r","").split("\n")
for idx in range(self.m_numcols):
self.m_datacols.append([])
if len(rows) == self.m_headlen:
return
for item in rows[self.m_headlen:]:
if item == "":
continue
cells = item.split(",")
for col in range(len(cells)):
if col == 0:
self.m_datacols[col].\
append(csvd.string_to_datetime(cells[col]))
else:
try:
self.m_datacols[col].append(float(cells[col]))
except ValueError:
self.m_datacols[col].append(str(cells[col]))
#store last date in the file
try:
self.m_last_init_date = self.m_datacols[0][-1]
except IndexError:
pass
