NameError: global name 'key_str' is not defined - python-2.5

Question

in below script i am getting the error
if not any(d['KEY'] == key_str for d in records):
NameError: global name 'key_str' is not defined
I am transposing a input file set of columns to rows and rows to columns.
please help:
if "Sales-Target" in fdmContext["LOCNAME"]:
filename = fdmContext["FILENAME"]
dim_cols = 7
period_dim_index = 0
input_filename = (os.path.abspath("E:/FDMEE/")+"\%s" % filename)
months = ['M%s' % x for x in range(1,13)]
first_row = True
headers = []
records = []
output_filename = "%s_out.%s" % (input_filename.split(".")[0],input_filename.split(".")[1])
input_f = open(input_filename)
for line in input_f:
if first_row:
headers = line.split(",")
headers = [x.rstrip() for x in headers]
else:
data = line.split(",")
for i in range(dim_cols,len(headers)):
key = data[:dim_cols]
del key[period_dim_index]
key.append(headers[i])
key_str = "_".join(key)
if not any(d['KEY'] == key_str for d in records):
record = {}
record["ACCOUNT"] = headers[i]
record["KEY"] = key_str
record["PERIODS"] = {}
for j in range(0,dim_cols):
if j == period_dim_index:
record["PERIODS"][data[j]] = data[i].rstrip()
else:
record[headers[j]] = data[j]
records.append(record)
else:
record = (d for d in records if d["KEY"] == key_str).next()
record["PERIODS"][data[period_dim_index]] = data[i].rstrip()
first_row = False
input_f.close()
output_f = open(output_filename,"w")
row=[]
[row.append(x) for x in headers[:dim_cols] if headers.index(x) != period_dim_index]
row.append("ACCOUNT")
[row.append(x) for x in months]
output_f.write("%s\n" % ",".join(row))
for record in records:
row = [record[x] for x in headers[:dim_cols] if headers.index(x) != period_dim_index]
row.append(record["ACCOUNT"])
for month in months:
if month in record["PERIODS"].keys():
row.append(record["PERIODS"][month])
else:
row.append("0")
output_f.write("%s\n" % ",".join(row))
output_f.close()