Python CSV - use dictionary for each cell - python

i hope my question makes sense. i am looking for a way to read a csv file, and map a dictionary to each cell. i can make it work without csv, but i am having a hard time making it work when reading a csv file.
note:
string0 would be cell A1 or row[0]
string1 would be cell B1 or row[1]
string2 would be cell C1 or row[2]
this is what i have so far:
dict0 = {'A':'CODE1', 'B':'CODE2'}
text0 = []
string0 = 'A'
dict1 = {'avenue':'ave', 'street':'st', 'road':'rd', 'court':'ct'}
text1 = []
string1 = '123 MAIN AVENUE'
dict2 = {'(':'', ')':'', '-':'', ' ':'', '/':'', '\\':''}
text2 = []
string2 = '(123) 456/7890'
for i in string0:
newcode = dict0.get(i,i)
text0.append(newcode)
print ' '.join(text0)
for i in string1.lower().split(' '):
newaddress = dict1.get(i.lower(),i)
text1.append(newaddress)
print ' '.join(text1)
for i in string2:
newphone = dict2.get(i,i)
text2.append(newphone)
print ''.join(text2)
the code above works exactly as i intend it to work, but im having a hard time trying to make it work when reading a csv file.
thank you very much
edit #1:***********************************************
here is an excerpt of sample1.csv:
A,123 MAIN STREET,(123) 456-7890
B,888 TEST ROAD,(222) 555-5555
sorry if the code isnt much cleaner/clearer, but that is why i am asking for guidance.
in essence, every column will have a dictionary associated with it, so that the "code" column will write "CODE1 or CODE2" depending on the value of cell A1 ("A" or "B").
column 2 will have dict1{} associated with it, and will clean up the address column.
column 3 will have dict2{} associated with it, and will remove (,),/,\ from the phone number column.
my issue is i do not know how to start the code. i can write the code if i set the cell information as variables (see me code above, variables: string0, string1, string2), but i do not know how i would start to iterate the csv file.
thank you
edit #2:***********************************************
here is my code when i try using import csv
dict0 = {'A':'CODE1', 'B':'CODE2'}
text0 = []
dict1 = {'avenue':'ave', 'street':'st', 'road':'rd', 'court':'ct'}
text1 = []
dict2 = {'(':'', ')':'', '-':'', ' ':'', '/':'', '\\':''}
text2 = []
import csv
with open('O:/sample1.csv', 'rb') as c:
reader = csv.reader(c)
for row in reader:
for i in row[0]:
newcode = dict0.get(i,i)
text0.append(newcode)
for i in row[1].lower().split(' '):
newaddress = dict1.get(i.lower(),i)
text1.append(newaddress)
for i in row[2]:
newphone = dict2.get(i,i)
text2.append(newphone)
print str(' '.join(text0)) + ',' + str(' '.join(text1)) + ',' + str(''.join(text2))
prints:
CODE1,123 main st,1234567890
CODE1 CODE2,123 main st 888 test rd,12345678902225555555
i would like to print:
CODE1,123 main st,1234567890
CODE2,888 test rd,2225555555
hopefully someone can help
thank you
edit #3 *********************************************************************************************************************
can the following be improved (syntax, indentation etc..):
sample1.csv:
A,123 MAIN STREET,(123) 456-7890
B,888 TEST ROAD,(222) 555-5555
here is the code:
import csv
newcsv = csv.writer(open('O:/csvfile1.csv', 'ab'))
with open('O:/sample1.csv', 'rb') as c:
reader = csv.reader(c)
dict0 = {'A':'CODE1', 'B':'CODE2'}
dict1 = {'avenue':'ave', 'street':'st', 'road':'rd', 'court':'ct'}
dict2 = {'(':'', ')':'', '-':'', ' ':'', '/':'', '\\':''}
# read element in *reader*
for row in reader:
text0 = []
text1 = []
text2 = []
newline = []
# read element in *row*
for i in row[0]:
newcode = dict0.get(i,i)
text0.append(newcode)
newline.append(' '.join(text0))
for i in row[1].lower().split(' '):
newaddress = dict1.get(i.lower(),i)
text1.append(newaddress)
newline.append(' '.join(text1))
for i in row[2]:
newphone = dict2.get(i,i)
text2.append(newphone)
newline.append(''.join(text2))
newcsv.writerow(newline)
print newline
prints the following:
['CODE1', '123 main st', '1234567890']
['CODE2', '888 test rd', '2225555555']
creates csvfile1.csv (using '|' as a 'cell delimiter') and its exactly what i want:
CODE1|123 main st|1234567890
CODE2|888 test rd|2225555555
just wondering if the above code can be improved/written in an more effective way.
thank you

The reason for the garbled output is that you are not clearing the text<n> variables on each cycle of the loop. While there is the fix below, I recommend reading at least how to define functions, rewriting the code without so many global variables so that you don't run into the same problems like now.
with open('O:/sample1.csv', 'rb') as c:
reader = csv.reader(c)
for row in reader:
text0 = []
text1 = []
text2 = []
for i in row[0]:
newcode = dict0.get(i,i)
text0.append(newcode)
for i in row[1].lower().split(' '):
newaddress = dict1.get(i.lower(),i)
text1.append(newaddress)
for i in row[2]:
newphone = dict2.get(i,i)
text2.append(newphone)
print str(' '.join(text0)) + ',' + str(' '.join(text1)) + ',' + str(''.join(text2))

Related

How do I parse this kind of text file with special separator

I need to parse the following text file into a dataframe, any suggestion about the methods?
Input:
('name: ', u'Jacky')
('male: ', True)
('hobby: ', u'play football and bascket')
('age: ', 24.0)
----------------
('name: ', u'Belly')
('male: ', True)
('hobby: ', u'dancer')
('age: ', 74.0)
----------------
('name: ', u'Chow')
('male: ', True)
('hobby: ', u'artist')
('age: ', 46.0)
output:
name male hobby age
jacky True football 24
...
I used regex to parse your text file :
import re
import pandas as pd
text_path = 'text.txt'
my_dict = {}
pattern = r"\('(\w+):\s+',\s+u*'*([a-zA-Z0-9\s.]*)'*\)"
with open(text_path, 'r') as txt:
for block in re.split(r"-+\n", txt.read()):
for line in filter(None, block.split('\n')):
col_name, value = re.search(pattern, line).group(1,2)
try:
value = int(float(value))
except ValueError:
value = True if value=='True' else False if value=='False' else value
if col_name in my_dict:
my_dict[col_name].append(value)
else:
my_dict[col_name] = [value]
df = pd.DataFrame(my_dict)
print(df)
Output :
name male hobby age
0 Jacky True play football and bascket 24
1 Belly True dancer 74
2 Chow True artist 46
Booleans values are not string but real bool True or False, numerical value (like age) are int (you could keep them as float) and not strings.
Ask me if you don't understand something.
I don't know any way to parse this data convention with usage of some existing parser so I suggest to build your own ones. Then I would use readlines() method on open file so it allows me to iterate over lines of data and apply correct parser to each row in iteration. Finally, I would combine data and create DataFrame. Example code is below:
import pandas as pd
import sys
def parse_from_weird_file_to_pandas_df(file):
with open(file, 'r') as f:
content = f.readlines()
name_vals = [_parse_text(content[line]) for line in range(0, len(content), 5)]
male_vals = [_parse_bool(content[line]) for line in range(1, len(content), 5)]
hobby_vals = [_parse_text(content[line]) for line in range(2, len(content), 5)]
age_vals = [_parse_int(content[line]) for line in range(3, len(content), 5)]
df_rows = zip(name_vals, male_vals, hobby_vals, age_vals)
df = pd.DataFrame(data=df_rows, columns=["name", "male", "hobby", "age"])
return df
def _parse_text(text_line):
text = text_line[text_line.find("u'") + 2: text_line.find("')")]
return text
def _parse_bool(bool_line):
val_bool = bool_line[bool_line.find("', ") + 3: bool_line.find(")")]
return True if val_bool == "True" else False
def _parse_int(int_line):
val_int = int_line[int_line.find("', ") + 3: int_line.find(")")]
return int(float(val_int))
If you wish to shorten 'play football and bascket' to just 'football' you can achieve this for example by creating list with all available hobbies, looping them through parsed hobby and returning the matching one.
Here is a quick code I made just before lunch, not optimised but seems to work (I did not remove the 'u'in the string and did not convert the int but you should be able to manage that ? If not let me kow and i will work on it after !
The .join remove unecessary char and I assume you only have 4 object every time...
file = open("yourfile.txt", 'r')
lines = file.readlines()
init = True
list_to_append = []
df = pd.DataFrame(columns=['name', 'male', 'hobby','age'])
for line in lines:
if '---' not in line:
line = line.split(',')[1]
processed_line = ''.join(c for c in line if c not in " ()'\n")
list_to_append.append(processed_line)
if len(list_to_append) == 4:
df.loc[len(df)] = list_to_append
list_to_append = []
else :
pass
file.close()

split() issues with pdf extractText()

I'm working on a minor content analysis program that I was hoping that I could have running through several pdf-files and return the sum of frequencies that some specific words are mentioned in the text. The words that are searched for are specified in a separate text file (list.txt) and can be altered. The program runs just fine through files with .txt format, but the result is completely different when running the program on a .pdf file. To illustrate, the test text that I have the program running trhough is the following:
"Hello
This is a product development notice
We’re working with innovative measures
A nice Innovation
The world that we live in is innovative
We are currently working on a new process
And in the fall, you will experience our new product development introduction"
The list of words grouped in categories are the following (marked in .txt file with ">>"):
innovation: innovat
product: Product, development, introduction
organization: Process
The output from running the code with a .txt file is the following:
Whereas the ouput from running it with a .pdf is the following:
As you can see, my issue is pertaining to the splitting of the words, where in the .pdf output i can have a string like "world" be split into 'w','o','rld'. I have tried to search for why this happens tirelessly, without success. As I am rather new to Python programming, I would appreciate any answe or direction to where I can fin and answer to why this happens, should you know any source.
Thanks
The code for the .txt is as follows:
import string, re, os
import PyPDF2
dictfile = open('list.txt')
lines = dictfile.readlines()
dictfile.close()
dic = {}
scores = {}
i = 2011
while i < 2012:
f = 'annual_report_' + str(i) +'.txt'
textfile = open(f)
text = textfile.read().split() # lowercase the text
print (text)
textfile.close()
i = i + 1
# a default category for simple word lists
current_category = "Default"
scores[current_category] = 0
# import the dictionary
for line in lines:
if line[0:2] == '>>':
current_category = line[2:].strip()
scores[current_category] = 0
else:
line = line.strip()
if len(line) > 0:
pattern = re.compile(line, re.IGNORECASE)
dic[pattern] = current_category
# examine the text
for token in text:
for pattern in dic.keys():
if pattern.match( token ):
categ = dic[pattern]
scores[categ] = scores[categ] + 1
print (os.path.basename(f))
for key in scores.keys():
print (key, ":", scores[key])
While the code for the .pdf is as follows:
import string, re, os
import PyPDF2
dictfile = open('list.txt')
lines = dictfile.readlines()
dictfile.close()
dic = {}
scores = {}
i = 2011
while i < 2012:
f = 'annual_report_' + str(i) +'.pdf'
textfile = open(f, 'rb')
text = PyPDF2.PdfFileReader(textfile)# lowercase the text
for pageNum in range(0, text.numPages):
texts = text.getPage(pageNum)
textfile = texts.extractText().split()
print (textfile)
i = i + 1
# a default category for simple word lists
current_category = "Default"
scores[current_category] = 0
# import the dictionary
for line in lines:
if line[0:2] == '>>':
current_category = line[2:].strip()
scores[current_category] = 0
else:
line = line.strip()
if len(line) > 0:
pattern = re.compile(line, re.IGNORECASE)
dic[pattern] = current_category
# examine the text
for token in textfile:
for pattern in dic.keys():
if pattern.match( token ):
categ = dic[pattern]
scores[categ] = scores[categ] + 1
print (os.path.basename(f))
for key in scores.keys():
print (key, ":", scores[key])

Returning a row that matches specified condition, and edit particular columns in row. Then write to csv file with changed row

I'm writing a python script that works with two csv files. Lets call them csv1.csv (original file to read) and csv2.csv (exact copy of csv1). The goal is to find the row and column in the csv file that corresponds to the the modified user-defined input.
csv format:(continues for about 2-3 thousand lines)
record LNLIM, ID_CO,OD_DV,ID_LN, ST_LN, ZST_LN, ID_LNLIM,LIMIT1_LNLIM, LIMIT2_LNLIM, LIMIT3_LNLIM
LNLIM, 'FPL', 'SOUT', '137TH_LEVEE_B', 'B', '137TH_AV', 'LEVEE', 'A', 1000, 1100, 1200
LNLIM, 'FPL', 'SOUT', '137TH_DAVIS_B', 'A', '137TH_AV', 'NEWTON', 'A', 1000, 1100, 1200
...
Let's say that the user is looking for 137TH_AV and NEWTON. I want to be able to go row by row and compare the two columns/row indices ST_LN and ZST_LN. If both columns match what the user inputted then I want to capture which row in the csv file that happened on, and use that information to edit the remaining columns LIMIT1_LNLIM LIMIT2_LNLIM LIMIT3_LNLIM on that row with new analog values.
I want to get the 3 new values provided by the user and edit a specific row, and a specific row element. Once I've found the place to replace the number values I want to overwrite csv2.csv with this edit.
Determining where the line segment is located in the array
import sys
import csv
import os
import shutil
LineSectionNames = []
ScadaNames = []
with open('Vulcan_Imp_Summary.csv', 'r') as file:
reader = csv.reader(file)
for row in reader:
LineSectionName = row[1]
ScadaName = row[29]
LineSectionNames.append(LineSectionName)
ScadaNames.append(ScadaName)
#Reformatting arrays for accurate references
LineSectionNames = [character.replace('\xa0', ' ') for character in LineSectionNames]
LineSectionNames = [character.replace('?', '-') for character in LineSectionNames]
ScadaNames = [character.replace('\xa0', ' ') for character in ScadaNames]
#Setting Line Section name as key and Scada name as value
ScadaDict = {}
for i in range(len(LineSectionNames)):
ScadaDict[LineSectionNames[i]] = ScadaNames[i]
#Prompt user for grammatical name of Line Section
print ('Enter the Line Section Name: (Example = Goulds-Princeton) \n')
user_input = input()
#Reference user input to dictionary value to convert input into SCADA format
def reformat():
print ('Searching for Line Section...' + user_input)
if user_input in ScadaDict:
value = ScadaDict[user_input]
print ('\n\t Match!\n')
else:
print ('The Line Section name you have entered was incorrect. Try again. \n Example = Goulds-Princeton')
reformat()
# Copying the exported file from Genesys
path = 'I://PSCO//DBGROUP//PatrickL//'
shutil.copyfile(path + 'lnlim_import.csv', path + 'lnlim_import_c.csv')
#Using the SCADA format to search through csv file
print ('Searching csv file for...' + user_input)
# Reading the copied file
record_lnlims = []
id_cos = []
id_dvs = []
id_lines = []
id_lns = []
st_lns = []
zst_lns = []
id_lnlims = []
limit1_lnlims = []
limit2_lnlims = []
limit3_lnlims = []
with open('lnlim_import_c.csv', 'r') as copy:
reader = csv.reader(copy)
for row in reader:
record_lnlim = row[0]
id_co = row[1]
id_dv = row[2]
id_line = row[3]
id_ln = row[4]
st_ln = row[5]
zst_ln = row[6]
id_lnlim = row[7]
limit1_lnlim = row[8]
limit2_lnlim = row[9]
limit3_lnlim = row[10]
record_lnlims.append(record_lnlim)
id_cos.append(id_co)
id_dvs.append(id_dv)
id_lines.append(id_line)
id_lns.append(id_ln)
st_lns.append(st_ln)
zst_lns.append(zst_ln)
id_lnlims.append(id_lnlim)
limit1_lnlims.append(limit1_lnlim)
limit2_lnlims.append(limit2_lnlim)
limit3_lnlims.append(limit3_lnlim)
#Reformatting the user input from GOULDS-PRINCETON to 'GOULDS' and 'PRINCETON'
input_split = user_input.split('-', 1)
st_ln1 = input_split[0]
zst_ln1 = input_split[1]
st_ln2 = st_ln1.upper()
zst_ln2 = zst_ln1.upper()
st_ln3 = "'" + str(st_ln2) + "'"
zst_ln3 = "'" + str(zst_ln2) + "'"
#Receiving analog values from user
print ('\n\t Found! \n')
print ('Enter the Specified Emergency Rating (A) for 110% for 7 minutes: ')
limit1_input = input()
print ('Enter the Specified Emergency Rating (A) for 120% for 7 minutes: ')
limit2_input = input()
print ('Enter the Specified Emergency Rating (A) for 130% for 5 minutes: ')
limit3_input = input()
Whenever I print the row_index it prints the initialized value of 0.
i = 0
row_index = 0
for i in range(len(st_lns)):
if st_ln3 == st_lns[i] and zst_ln3 == zst_lns[i]:
row_index = i
print(row_index)
limit1_input = limit1_lnlims[row_index]
limit2_input = limit2_lnlims[row_index]
limit3_input = limit3_lnlims[row_index]
csv_list = []
csv_list.append(record_lnlims)
csv_list.append(id_cos)
csv_list.append(id_dvs)
csv_list.append(id_lines)
csv_list.append(st_lns)
csv_list.append(zst_lns)
csv_list.append(id_lnlims)
csv_list.append(limit1_lnlims)
csv_list.append(limit2_lnlims)
csv_list.append(limit3_lnlims)
#Editing the csv file copy to implement new analog values
with open('lnlim_import_c.csv', 'w') as edit:
for x in zip(csv_list):
edit.write("{0}\t{1}\t{2}\t{3}\t{4}\t{5}\t{6}\t{7}\t{8}\t{9}\t{10}\n".format(x))

Python CSV module, add column to the side, not the bottom

I am new in python, and I need some help. I made a python script that takes two columns from a file and copies them into a "new file". However, every now and then I need to add columns to the "new file". I need to add the columns on the side, not the bottom. My script adds them to the bottom. Someone suggested using CSV, and I read about it, but I can't make it in a way that it adds the new column to the side of the previous columns. Any help is highly appreciated.
Here is the code that I wrote:
import sys
import re
filetoread = sys.argv[1]
filetowrite = sys.argv[2]
newfile = str(filetowrite) + ".txt"
openold = open(filetoread,"r")
opennew = open(newfile,"a")
rline = openold.readlines()
number = int(len(rline))
start = 0
for i in range (len(rline)) :
if "2theta" in rline[i] :
start = i
for line in rline[start + 1 : number] :
words = line.split()
word1 = words[1]
word2 = words[2]
opennew.write (word1 + " " + word2 + "\n")
openold.close()
opennew.close()
Here is the second code I wrote, using CSV:
import sys
import re
import csv
filetoread = sys.argv[1]
filetowrite = sys.argv[2]
newfile = str(filetowrite) + ".txt"
openold = open(filetoread,"r")
rline = openold.readlines()
number = int(len(rline))
start = 0
for i in range (len(rline)) :
if "2theta" in rline[i] :
start = i
words1 = []
words2 = []
for line in rline[start + 1 : number] :
words = line.split()
word1 = words[1]
word2 = words[2]
words1.append([word1])
words2.append([word2])
with open(newfile, 'wb') as file:
writer = csv.writer(file, delimiter= "\n")
writer.writerow(words1)
writer.writerow(words2)
These are some samples of input files:
https://dl.dropbox.com/u/63216126/file5.txt
https://dl.dropbox.com/u/63216126/file6.txt
My first script works "almost" great, except that it writes the new columns at the bottom and I need them at side of the previous columns.
The proper way to use writerow is to give it a single list that contains the data for all the columns.
words.append(word1)
words.append(word2)
writer.writerow(words)

How to extract column and row in csv using python

I have this input in a file.csv
"","min","max","rainfall","days_clear"
"Missouri",-2,10,300,23
"Amsterdam",-3,5,1212,34
"LA",10,20,1000,54
I wanted to write a simple program to find the city with the lowest rainfall which is Missouri in this case. How can I do that using Python csv reader?
I can try extract the items but unfortunately the first row of the file has to be there.
I wanted to have something like count[Missouri]=300
count[Amsterdam]=1212 etc.. so that I can do a minimum and reference back to print the city.
Please advise. Thanks.
import csv
def main():
with open('file.csv', 'rb') as inf:
data = [(int(row['rainfall']), row['']) for row in csv.DictReader(inf)]
data.sort()
print data[0]
if __name__=="__main__":
main()
returns
(300, 'Missouri')
One way to do this would be to use the csv module's DictReader class to write a function to extract the column of data. DictReader will take care of handling the first row of field names automatically. The built-in min() function can then be used to determine the item with the smallest value in the column.
import csv
def csv_extract_col(csvinput, colname, key):
""" extract a named column from a csv stream into a dictionary
colname: name of columm to extract
key: name of another columm to use as keys in returned dict
"""
col = {}
for row in csv.DictReader(csvinput):
col[row[key]] = row[colname]
return col
if __name__=='__main__':
import StringIO
csvdata = """\
"","min","max","rainfall","days_clear" # field name row
"Missouri",-2,10,300,23
"Amsterdam",-3,5,1212,34
"LA",10,20,1000,54
"""
csvfile = StringIO.StringIO(csvdata)
rainfall = csv_extract_col(csvfile, 'rainfall', '')
print rainfall
# {'Amsterdam': '1212', 'LA': '1000', 'Missouri': '300'}
print min(rainfall.iteritems(), key=lambda r: float(r[1]))
# ('Missouri', '300')
import StringIO
import csv
example = """"","min","max","rainfall","days_clear"
"Missouri",-2,10,300,23
"Amsterdam",-3,5,1212,34
"LA",10,20,1000,54
"""
data_in = StringIO.StringIO(example)
#data_in = open('mycsvdata.csv')
def read_data(data_in):
reader = csv.reader(data_in)
cols = []
results = {}
for row in reader:
if not cols:
cols = row
continue
row = [ int(x) if x.lstrip('-').isdigit() else x for x in row ]
results[row[0]] = dict(zip(cols[1:],row[1:]))
return results
data = read_data(data_in)
min(data.items(),key=lambda x: x[1].get('rainfall'))
Returns
('Missouri', {'max': 10, 'days_clear': 23, 'rainfall': 300, 'min': -2})
To read from a file, you need to remove all code that deals with a string:
reader = csv.reader(open('file.csv', 'rb'))
rainfall = csv_extract_col(reader, 'rainfall', '')
Update: Sorry, it neads a bit more work than that. The first arg of csv_extract_col will be used as the first arg of csv.DictReader so (in this case) it should be an open file object, and should never be a csv.reader instance. See below:
import csv
### def csv_extract_col(csvinput, colname, key):
### exactly as provided by #martineau
if __name__ == '__main__':
import sys
filename, data_col_name, key_col_name = sys.argv[1:4]
input_file_object = open(filename, 'rb')
result_dict = csv_extract_col(input_file_object, data_col_name, key_col_name)
print result_dict
print min(result_dict.iteritems(), key=lambda r: float(r[1]))
Results:
command-prompt>\python27\python joj_csv.py joj.csv rainfall ""
{'Amsterdam': '1212', 'LA': '1000', 'Missouri': '300'}
('Missouri', '300')
command-prompt>\python27\python joj_csv.py joj.csv days_clear ""
{'Amsterdam': '34', 'LA': '54', 'Missouri': '23'}
('Missouri', '23')
Update 2 in response to comment """there must be something i missed out.. i tried.. [what looks like #martineau's function] with the above main function you define. Then in my shell, i define python rainfall "". But it gives me KeyError: 'rainfall'"""
Two possibilities:
(1) You made a mistake patching the pieces of source code together. Check your work.
(2) Your file doesn't have the expected heading row contents. Try some debugging e.g. change #martineau's code so that you can insert a print statement etc. to show what the csv.DictReader thinks about your heading row:
reader = csv.DictReader(csvinput)
print "fieldnames", reader.fieldnames
assert colname in reader.fieldnames
assert key in reader.fieldnames
for row in reader:
If you are still stuck, show us ALL of your code plus the full traceback and error message -- either edit your question or put it up on pastbin or dropbox; DON'T put it into a comment!!
My code for cases in which there are several cities having the same minimum or several cities having the same maximum:
import csv
def minmax_col(filename,key,colname):
with open(filename,'rb') as csvfile:
rid = csv.DictReader(csvfile,
fieldnames=None,
quoting=csv.QUOTE_NONNUMERIC)
mini = float('inf')
maxi = float('-inf')
limin = limax =[]
for row in rid:
if row[colname] == maxi:
limax.append(row[key])
elif row[colname] > maxi:
maxi = row[colname]
limax = [row[key]]
if row[colname] == mini:
limin.append(row[key])
elif row[colname] < mini:
mini = row[colname]
limin = [row[key]]
return (key,(maxi,limax),(mini,limin))
key = 'rainfall'
city,(Ma,liMa),(mi,limi) = minmax_col('filename.csv','',key)
print 'Cities analysed on ' + repr(key) + ' parameter :'
print 'maximum==',Ma,' cities :',', '.join(liMa)
print 'minimum==',mi,' cities :',', '.join(limi)
print
key = 'min'
city,(Ma,liMa),(mi,limi) = minmax_col('filename.csv','',key)
print 'Cities analysed on ' + repr(key) + ' parameter :'
print 'maximum==',Ma,' cities :',', '.join(liMa)
print 'minimum==',mi,' cities :',', '.join(limi)
On a file like that:
"","min","max","rainfall","days_clear"
"Missouri",-2,10,300,23
"Amsterdam",-3,5,1212,34
"Oslo",-2,8,800,12
"LA",10,20,1000,54
"Kologoro",28,45,1212,1
the result is
Cities analysed according the 'rainfall' parameter :
maximum== 1212.0 cities : Amsterdam, Kologoro
minimum== 300.0 cities : Missouri
Cities analysed according the 'min' parameter :
maximum== 28.0 cities : Kologoro
minimum== -3.0 cities : Amsterdam

Categories