我正在进行文本处理并使用“readline()”函数，如下所示：ifd = open(...)

for line in ifd:

while (condition)

do something...

line = ifd.readline()

condition = ....

当条件变为false时，我需要倒带指针，以便“for”循环再次读取同一行。在

在ifd.fseek公司()后面跟readline是给我一个'\n'字符。如何倒带指针，以便重新读取整行。在

^{pr2}$

这是我的代码labtestnames = sorted(tmp)

#Now read each line in the inFile and write into outFile

ifd = open(inFile, "r")

ofd = open(outFile, "w")

#read the header

header = ifd.readline() #Do nothing with this line. Skip

#Write header into the output file

nl = "mrn\tspecimen_id\tlab_number\tlogin_dt\tfluid"

offset = len(nl.split("\t"))

nl = nl + "\t" + "\t".join(labtestnames)

ofd.write(nl+"\n")

lenFields = len(nl.split("\t"))

print "Reading the input file and converting into modified file for further processing (correlation analysis etc..)"

prevTup = (0,0,0)

rowComplete = 0

k=0

for line in ifd:

k=k+1

if (k==200): break

items = line.rstrip("\n").split("\t")

if((items[0] =='')):

continue

newline= list('' for i in range(lenFields))

newline[0],newline[1],newline[3],newline[2],newline[4] = items[0], items[1], items[3], items[2], items[4]

ltests = []

ltvals = []

while(cmp(prevTup, (items[0], items[1], items[3])) == 0): # If the same mrn, lab_number and specimen_id then fill the same row. else create a new row.

ltests.append(items[6])

ltvals.append(items[7])

pos = ifd.tell()

line = ifd.readline()

prevTup = (items[0], items[1], items[3])

items = line.rstrip("\n").split("\t")

rowComplete = 1

if (rowComplete == 1): #If the row is completed, prepare newline and write into outfile

indices = [labtestnames.index(x) for x in ltests]

j=0

ifd.seek(pos)

for i in indices:

newline[i+offset] = ltvals[j]

j=j+1

if (rowComplete == 0): #

currTup = (items[0], items[1], items[3])

ltests = items[6]

ltvals = items[7]

pos = ifd.tell()

line = ifd.readline()

items = line.rstrip("\n").split("\t")

newTup = (items[0], items[1], items[3])

if(cmp(currTup, newTup) == 0):

prevTup = currTup

ifd.seek(pos)

continue

else:

indices = labtestnames.index(ltests)

newline[indices+offset] = ltvals

ofd.write(newline+"\n")