I have recently stumbled upon a task utilizing some CSV files that are, to say the least, very poorly organized, with one cell containing what should be multiple separate columns. I would like to use this data in a Python script but want to know if it is possible to delete a portion of the row (all of it after a certain point) then write that to a dictionary.
Although I can't show the exact contents of the CSV, it looks like this:
useful. useless useless useless useless
I understand that this will most likely require either a regular expression or an endswith statement, but doing all of that to a CSV file is beyond me. Also, the period written after useful on the CSV should be removed as well, and is not a typo.
If you know the character you want to split on you can use this simple method:
good_data = bad_data.split(".")[0]
good_data = good_data.strip() # remove excess whitespace at start and end
This method will always work. split will return a tuple which will always have at least 1 entry (the full string). Using index may throw an exception.
You can also limit the # of splits that will happen if necessary using split(".", N).
https://docs.python.org/2/library/stdtypes.html#str.split
>>> "good.bad.ugly".split(".", 1)
['good', 'bad.ugly']
>>> "nothing bad".split(".")
['nothing bad']
>>> stuff = "useful useless"
>>> stuff = stuff[:stuff.index(".")]
ValueError: substring not found
Actual Answer
Ok then notice that you can use indexing for strings just like you do for lists. I.e. "this is a very long string but we only want the first 4 letters"[:4] gives "this". If we now new the index of the dot we could just get what you want like that. For exactly that strings have the index method. So in total you do:
stuff = "useful. useless useless useless useless"
stuff = stuff[:stuff.index(".")]
Now stuff is very useful :).
In case we are talking about a file containing multiple lines like that you could do it for each line. Split that line at , and put all in a dictionary.
data = {}
with open("./test.txt") as f:
for i, line in enumerate(f.read().split("\n")):
csv_line = line[:line.index(".")]
for j,col in enumerate(csv_line.split(",")):
data[(i,j)] = col
How one would do this
Notice that most people would not want to do it by hand. It is a common task to work on tabled data and there is a library called pandas for that. Maybe it would be a good idea to familiarise yourself a bit more with python before you dive into pandas though. I think a good point to start is this. Using pandas your task would look like this
import pandas as pd
pd.read_csv("./test.txt", comment=".")
giving you what is called a dataframe.
I have a really weird python problem. I have already asked several colleagues who all had no idea how it happened and how it could be solved.
I have a shallow dict of strings that I receive from an API call and I want to assign some of those values to a new dict.
This is what the first dict looks like. Just a bunch of strings:
I assign some values from dict1 to some keys in dict2. Really basic
dict2={}
dict2['access_key'] = dict1['access_key']
dict2['secret_access_key'] = dict1['secret_access_key'],
dict2['session_token'] =dict1['session_token'],
dict2['region'] = dict1['region']
Then this happens. The values for "secret access key" and "session_token" are turned into tuples. "access_key" and "region" remain strings
I have already tried initialising the values as strings, accessing the first entry of the tuple and casting the value to a string. All of that did not change anything. It seems like the value is assigned just fine and then something weird happens that turns it into a tuple
This is a screenshot of my Interpreter settings. I am using Pyython 3.6
I am really going crazy over this one :-/ Any help would be greatly appreciated
You have trailing commas at the end of two of your calls. This is why the strings are transformed to tuples.
My dear friend , the reason you have this problem is in Python tuple is idetified by commas.
You can try this code
a = 1,
print(a,type(a))
b = 1
print(b,type(b))
So I update your code to this:
dict2={}
dict2['access_key'] = dict1['access_key']
# please notes the end !
# dict2['secret_access_key'] = dict1['secret_access_key'],
# dict2['session_token'] =dict1['session_token'],
# above is the origin code
dict2['secret_access_key'] = dict1['secret_access_key']
dict2['session_token'] =dict1['session_token']
dict2['region'] = dict1['region']
I think this will help!
Try the following by removing the trailing commas:
dict2={}
dict2['access_key'] = dict1['access_key']
dict2['secret_access_key'] = dict1['secret_access_key']
dict2['session_token'] =dict1['session_token']
dict2['region'] = dict1['region']
My code is
import pymysql
conn=pymysql.connect(host=.................)
curs=conn.cursor()
import csv
f=open('./kospilist.csv','r')
data=f.readlines()
data_kp=[]
for i in data:
data_kp.append(i[:-1])
c = csv.writer(open("./test_b.csv","wb"))
def exportFunc():
result=[]
for i in range(0,len(data_kp)):
xp="select date from " + data_kp[i] + " where price is null"
curs.execute(xp)
result= curs.fetchall()
for row in result:
c.writerow(data_kp[i])
c.writerow(row)
c.writerow('\n')
exportFunc()
data_kp is reading the tables name
the tables' names are like this (string, ex: a000010)
I collect table names from here.
Then, execute and get the result.
The actual output of my code is ..
My expectation is
(not 3 columns.. there are 2000 tables)
I thought my code is near the answer... but it's not working..
My work is almost done, but I couldn't finish this part.
I had googled for almost 10 hours..
I don't know how.. please help
I think something is wrong with these part
for row in result:
c.writerow(data_kp[i])
c.writerow(row)
The csvwriter.writerow method allows you to write a row in your output csv file. This means that once you have called the writerow method, the line is wrote and you can't come back to it. When you write the code:
for row in result:
c.writerow(data_kp[i])
c.writerow(row)
You are saying:
"For each result, write a line containing data_kp[i] then write a
line containing row."
This way, everything will be wrote verticaly with alternation between data_kp[i] and row.
What is surprising is that it is not what we get in your actual output. I think that you've changed something. Something like that:
c.writerow(data_kp[i])
for row in result:
c.writerow(row)
But this has not entirely solved your issue, obviously: The names of the tables are not correctly displayed (one character on each column) and they are not side-by-side. So you have 2 problems here:
1. Get the table name in one cell and not splitted
First, let's take a look at the documentation about the csvwriter:
A row must be an iterable of strings or numbers for Writer objects
But your data_kp[i] is a String, not an "iterable of String". This can't work! But you don't get any error either, why? This is because a String, in python, may be itself considered as an iterable of String. Try by yourself:
for char in "abcde":
print(char)
And now, you have probably understood what to do in order to make the things work:
# Give an Iterable containing only data_kp[i]
c.writerow([data_kp[i]])
You have now your table name displayed in only 1 cell! But we still have an other problem...
2. Get the table names displayed side by side
Here, it is a problem in the logic of your code. You are browsing your table names, writing lines containing them and expect them to be written side-by-side and get columns of dates!
Your code need a little bit of rethinking because csvwriter is not made for writing columns but lines. We'll then use the zip_longest function of the itertools module. One can ask why don't I use the zip built-in function of Python: this is because the columns are not said to be of equal size and the zip function will stop once it reached the end of the shortest list!
import itertools
c = csv.writer(open("./test_b.csv","wb"))
# each entry of this list will contain a column for your csv file
data_columns = []
def exportFunc():
result=[]
for i in range(0,len(data_kp)):
xp="select date from " + data_kp[i] + " where price is null"
curs.execute(xp)
result= curs.fetchall()
# each column starts with the name of the table
data_columns.append([data_kp[i]] + list(result))
# the * operator explode the list into arguments for the zip function
ziped_columns = itertools.zip_longest(*data_columns, fillvalue=" ")
csvwriter.writerows(ziped_columns)
Note:
The code provided here has not been tested and may contain bugs. Nevertheless, you should be able (by using the documentation I provided) to fix it in order to make it works! Good luck :)
I have a problem where the I will get info from an API and the info will be returned like:
[{"market_id":"16","coin":"Dogecoin","code":"DOGE","exchange":"BTC","last_price":"0.00000025","yesterday_price":"0.00000025","change":"0.00","24hhigh":"0.00000026","24hlow":"0.00000025","24hvol":"6.732","top_bid":"0.00000025","top_ask":"0.00000026"}]
That makes it really hard to call the price for example. So I was wondering if there would be a way to get rid of the list [ ] and still keep that data? Thanks a bunch in advance!
Sure -- I'm assuming you've already parsed the JSON -- and since you only want to keep the first element (because there apparently is only one element), you can do:
data = data[0]
import json
data = '[{"market_id":"16","coin":"Dogecoin","code":"DOGE","exchange":"BTC","last_price":"0.00000025","yesterday_price":"0.00000025","change":"0.00","24hhigh":"0.00000026","24hlow":"0.00000025","24hvol":"6.732","top_bid":"0.00000025","top_ask":"0.00000026"}]'
# since the list only contains one element (the dict), we'll access it with [0]
dictionary = json.loads(data)[0]
print dictionary["last_price"]
To start I am a complete new comer to Python and programming anything other than web languages.
So, I have developed a script using Python as an interface between a piece of Software called Spendmap and an online app called Freeagent. This script works perfectly. It imports and parses the text file and pushes it through the API to the web app.
What I am struggling with is Spendmap exports multiple lines per order where as Freeagent wants One line per order. So I need to add the cost values from any orders spread across multiple lines and then 'flatten' the lines into One so it can be sent through the API. The 'key' field is the 'PO' field. So if the script sees any matching PO numbers, I want it to flatten them as per above.
This is a 'dummy' example of the text file produced by Spendmap:
5090071648,2013-06-05,2013-09-05,P000001,1133997,223.010,20,2013-09-10,104,xxxxxx,AP
COMMENT,002091
301067,2013-09-06,2013-09-11,P000002,1133919,42.000,20,2013-10-31,103,xxxxxx,AP
COMMENT,002143
301067,2013-09-06,2013-09-11,P000002,1133919,359.400,20,2013-10-31,103,xxxxxx,AP
COMMENT,002143
301067,2013-09-06,2013-09-11,P000003,1133910,23.690,20,2013-10-31,103,xxxxxx,AP
COMMENT,002143
The above has been formatted for easier reading and normally is just one line after the next with no text formatting.
The 'key' or PO field is the first bold item and the second bold/italic item is the cost to be totalled. So if this example was to be passed through the script id expect the first row to be left alone, the Second and Third row costs to be added as they're both from the same PO number and the Fourth line to left alone.
Expected result:
5090071648,2013-06-05,2013-09-05,P000001,1133997,223.010,20,2013-09-10,104,xxxxxx,AP
COMMENT,002091
301067,2013-09-06,2013-09-11,P000002,1133919,401.400,20,2013-10-31,103,xxxxxx,AP
COMMENT,002143
301067,2013-09-06,2013-09-11,P000003,1133910,23.690,20,2013-10-31,103,xxxxxx,AP
COMMENT,002143
Any help with this would be greatly appreciated and if you need any further details just say.
Thanks in advance for looking!
I won't give you the solution. But you should:
Write and test a regular expression that breaks the line down into its parts, or use the CSV library.
Parse the numbers out so they're decimal numbers rather than strings
Collect the lines up by ID. Perhaps you could use a dict that maps IDs to lists of orders?
When all the input is finished, iterate over that dict and add up all orders stored in that list.
Make a string format function that outputs the line in the expected format.
Maybe feed the output back into the input to test that you get the same result. Second time round there should be no changes, if I understood the problem.
Good luck!
I would use a dictionary to compile the lines, using get(key,0.0) to sum values if they exist already, or start with zero if not:
InputData = """5090071648,2013-06-05,2013-09-05,P000001,1133997,223.010,20,2013-09-10,104,xxxxxx,AP COMMENT,002091
301067,2013-09-06,2013-09-11,P000002,1133919,42.000,20,2013-10-31,103,xxxxxx,AP COMMENT,002143
301067,2013-09-06,2013-09-11,P000002,1133919,359.400,20,2013-10-31,103,xxxxxx,AP COMMENT,002143
301067,2013-09-06,2013-09-11,P000003,1133910,23.690,20,2013-10-31,103,xxxxxx,AP COMMENT,002143"""
OutD = {}
ValueD = {}
for Line in InputData.split('\n'):
# commas in comments won't matter because we are joining after anyway
Fields = Line.split(',')
PO = Fields[3]
Value = float(Fields[5])
# set up the output string with a placeholder for .format()
OutD[PO] = ",".join(Fields[:5] + ["{0:.3f}"] + Fields[6:])
# add the value to the old value or to zero if it is not found
ValueD[PO] = ValueD.get(PO,0.0) + Value
# the output is unsorted by default, but you could sort or preserve original order
for POKey in ValueD:
print OutD[POKey].format(ValueD[POKey])
P.S. Yes, I know Capitals are for Classes, but this makes it easier to tell what variables I have defined...