How do I convert '$ -' from a string to a float using pandas? - python

I have some financial information that I've kept on an excel document for a while and I'd like to run some python code on it, but I'm having some issues converting the objects types to floats. The problem seems to be the '$ -'
This is how the data looks when loaded in:
import pandas as pd
dfData = {'Item': ['Product 1','Product 2','Product 3'],
'Cost': [14.87,'-9.47','$ -']
}
df = pd.DataFrame(dfData,columns=['Item','Cost'])
df
Item Cost
0 Product 1 14.87
1 Product 2 -9.47
2 Product 3 $ -
I've tried:
df['Cost'] = df['Cost'].str.replace('$','').str.replace(' ','').astype('float')
...as well as other similar str.replace commands, but I keep getting the following error:
ValueError: could not convert string to float: ''
This is my first stack overflow post, so go easy on me! I have looked all over for a solution, but for some reason can't find one addressing this specific problem. I can't replace the '-' either, because row 1 has it indicating a negative value.

You don't need to chain str.replace, you can just use replace:
df['Cost'] = df['Cost'].replace({'\$': '', '-': '-0'}, regex=True).astype(float)
print(df)
# Output
Item Cost
0 Product 1 14.87
1 Product 2 -9.47
2 Product 3 -0.00

Related

TypeError: unhashable type: 'list' when I try to do a pivot from a column in pandas

My Python code takes a bank statement from Excel and creates a dataframe that categorises each transaction based on description.
Example code:
import pandas as pd
import openpyxl
import datetime as dt
import numpy as np
dff = pd.DataFrame({'Date': ['20221003', '20221005'],
'Tran Type': ['BOOK TRANSFER CREDIT', 'ACH DEBIT'],
'Debit Amount': [0.00, -220000.00],
'Credit Amount': [182.90, 0.0],
'Description': ['BOOK TRANSFER CREDIT FROM ACCOUNT 98754877', 'USREF2548 ACH OFFSET'],
'Amount': [-220000.00, 182.90]})
Then the bit that adds a column that categorises it if certain words appear in the description:
import re
dff['Category'] = dff['Description'].str.findall('Ref|BCA|Fund|Transfer', flags=re.IGNORECASE)
Output:
What it looks like
But this code will not work. Any ideas why?
pivotf = dff
pivotf = pd.pivot_table(pivotf,
index=["Date"], columns="Category",
values=['Amount'],
margins=False, margins_name="Total")
The error message is TypeError: unhashable type: 'list'
When I change columns from "Category" to anything else, it works fine. I have tried converting the column from object to string but this doesn't actually convert it.
you can use explode() function:
dff['Category'] = dff['Description'].str.findall('Ref|BCA|Fund|Transfer', flags=re.IGNORECASE).explode()
print(dff)
Returning:
Date Tran Type ... Amount Category
0 20221003 BOOK TRANSFER CREDIT ... -220000.0 TRANSFER
1 20221005 ACH DEBIT ... 182.9 REF
If Category column has multiple values you have to use it like this:
dff['Category'] = dff['Description'].str.findall('Ref|BCA|Fund|Transfer', flags=re.IGNORECASE)
dff=dff.explode('Category')
This is because the output of findall() is a list:
Return all non-overlapping matches of pattern in string, as a list of strings or tuples
Which is not a valid type when using pivot_table(). Add str[0] at the end if you expect to only have one find per Description/row and it should work:
dff['Category'] = dff['Description'].str.findall('Ref|BCA|Fund|Transfer', flags=re.IGNORECASE).str[0]
However, it may be more efficient under this scenario, to use search() which would be the perfect fit for this case:
dff['Category'] = dff['Description'].str.search('Ref|BCA|Fund|Transfer', flags=re.IGNORECASE)
Regardless of the approach, you will get as final output:
Amount
Category REF TRANSFER
Date
20221003 NaN -220000.0
20221005 182.9 NaN
Otherwise, you can use explode() as #Clenage suggests but, as shown here, it would lead to a potential issue of duplicated values because of different Categories:
pivotf = pd.pivot_table(pivotf.explode('Category'), index=["Date"], columns="Category",values=['Amount'],
margins=False, margins_name="Total")
Outputting for example:
Category BCA FUND REF TRANSFER
Date
20221003 -220000.0 -220000.0 NaN -220000.0
20221005 NaN NaN 182.9 NaN
In which case, it's untrue that for 2022-10-03 there was a total of -220000 * 3 money movement.

Unable to convert comma separated integers and non-integer values to float in a series column in Python

Loading in the data
in: import pandas as pd
in: df = pd.read_csv('name', sep = ';', encoding='unicode_escape')
in : df.dtypes
out: amount object
I have an object column with amounts like 150,01 and 43,69. Thee are about 5,000 rows.
df['amount']
0 31
1 150,01
2 50
3 54,4
4 32,79
...
4950 25,5
4951 39,5
4952 75,56
4953 5,9
4954 43,69
Name: amount, Length: 4955, dtype: object
Naturally, I tried to convert the series into the locale format, which suppose to turn it into a float format. I came back with the following error:
In: import locale
setlocale(LC_NUMERIC, 'en_US.UTF-8')
Out: 'en_US.UTF-8'
In: df['amount'].apply(locale.atof)
Out: ValueError: could not convert string to float: ' - '
Now that I'm aware that there are non-numeric values in the list, I tried to use isnumeric methods to turn the non-numeric values to become NaN.
Unfortunately, due to the comma separated structure, all the values would turn into -1.
0 -1
1 -1
2 -1
3 -1
4 -1
..
4950 -1
4951 -1
4952 -1
4953 -1
4954 -1
Name: amount, Length: 4955, dtype: int64
How do I turn the "," values to "." by first removing the "-" values? I tried .drop() or .truncate it does not help. If I replace the str",", " ", it would also cause trouble since there is a non-integer value.
Please help!
Documentation that I came across
-https://stackoverflow.com/questions/21771133/finding-non-numeric-rows-in-dataframe-in-pandas
-https://stackoverflow.com/questions/56315468/replace-comma-and-dot-in-pandas
p.s. This is my first post, please be kind
Sounds like you have a European-style CSV similar to the following. Provide actual sample data as many comments asked for if your format is different:
data.csv
thing;amount
thing1;31
thing2;150,01
thing3;50
thing4;54,4
thing5;1.500,22
To read it, specify the column, decimal and thousands separator as needed:
import pandas as pd
df = pd.read_csv('data.csv',sep=';',decimal=',',thousands='.')
print(df)
Output:
thing amount
0 thing1 31.00
1 thing2 150.01
2 thing3 50.00
3 thing4 54.40
4 thing5 1500.22
Posting as an answer since it contains multi-line code, despite not truly answering your question (yet):
Try using chardet. pip install chardet to get the package, then in your import block, add import chardet.
When importing the file, do something like:
with open("C:/path/to/file.csv", 'r') as f:
data = f.read()
result = chardet.detect(data.encode())
charencode = result['encoding']
# now re-set the handler to the beginning and re-read the file:
f.seek(0, 0)
data = pd.read_csv(f, delimiter=';', encoding=charencode)
Alternatively, for reasons I cannot fathom, passing engine='python' as a parameter works often. You'd just do
data = pd.read_csv('C:/path/to/file.csv', engine='python')
#Mark Tolonen has a more elegant approach to standardizing the actual data, but my (hacky) way of doing it was to just write a function:
def stripThousands(self, df_column):
df_column.replace(',', '', regex=True, inplace=True)
df_column = df_column.apply(pd.to_numeric, errors='coerce')
return df_column
If you don't care about the entries that are just hyphens, you could use a function like
def screw_hyphens(self, column):
column.replace(['-'], np.nan, inplace=True)
or if np.nan values will be a problem, you can just replace it with column.replace('-', '', inplace=True)
**EDIT: there was a typo in the block outlining the usage of chardet. it should be correct now (previously the end of the last line was encoding=charenc)

Extract prefix from string in dataframe column where exists in a list

Looking for some help.
I have a pandas dataframe column and I want to extract the prefix where such prefix exists in a separate list.
pr_list = ['1 FO-','2 IA-']
Column in df is like
PartNumber
ABC
DEF
1 FO-BLABLA
2 IA-EXAMPLE
What I am looking for is to extract the prefix where present, put in a new column and leave the rest of the string in the original column.
PartNumber Prefix
ABC
DEF
BLABLA 1 FO-
EXAMPLE 2 IA-
Have tried some things like str.startswith but a bit of a python novice and wasn't able to get it to work.
much appreciated
EDIT
Both solutions below work on the test data, however I am getting an error
error: nothing to repeat at position 16
Which suggests something askew in my dataset. Not sure what position 16 refers to but looking at both the prefix list and PartNumber column in position 16 nothing seems out of the ordinary?
EDIT 2
I have traced it to have an * in the pr_list seems to be throwing it. is * some reserved character? is there a way to break it out so it is read as text?
You can try:
df['Prefix']=df.PartNumber.str.extract(r'({})'.format('|'.join(pr_list))).fillna('')
df.PartNumber=df.PartNumber.str.replace('|'.join(pr_list),'')
print(df)
PartNumber Prefix
0 ABC
1 DEF
2 BLABLA 1 FO-
3 EXAMPLE 2 IA-
Maybe it's not what you are looking for, but may it help.
import pandas as pd
pr_list = ['1 FO-','2 IA-']
df = pd.DataFrame({'PartNumber':['ABC','DEF','1 FO-BLABLA','2 IA-EXAMPLE']})
extr = '|'.join(x for x in pr_list)
df['Prefix'] = df['PartNumber'].str.extract('('+ extr + ')', expand=False).fillna('')
df['PartNumber'] = df['PartNumber'].str.replace('|'.join(pr_list),'')
df

Best way to match list of words with a list of job descriptions python

Here is my problem (I'm working on python) :
I have a Dataframe with columns: Index(['job_title', 'company', 'job_label', 'description'], dtype='object')
And I have a list of words that contains 300 skills:
keywords = ["C++","Data Analytics","python","R", ............ "Django"]
I need to match those keywords with each of the jobs descriptions and obtain a new dataframe saying if is true or false that C++ is in job description[0]...job description[1], job description[2] and so on.
My new dataframe will be:
columns : ['job_title', 'company', 'description', "C++", "Data Analytics",
....... "Django"]
Where each column of keywords said true or false if it match(is found) or not on the job description.
There might be another ways to structure the dataframe (I'm listening suggestions).
Hope I'm clear with my question. I try regex but I can't make it iterate trough each row, I try with a loop using "fnmatch" library and I can't make it work. The best approach so far was:
df["microservice"]= df.description.str.contains("microservice")
df["cloud-based architecture"] = df.description.str.contains("cloud-based architecture")
df["service oriented architecture"] = df.description.str.contains("service oriented architecture")
However, First I could not manage to make it loop trough each rows of description column, so i have to input 300 times the code with each word (it doesn't make sense). Second, trough this way, I have problems with few words such as "R" because it find the letter R in each description, so it will pull true in each of them.
Iterate over list of keywords and extract each column from the description one:
for name in keywords:
df[name] = df['description'].apply(lambda x: True if name in x else False)
EDIT:
That doesn't solve the problem with R. To do so you could add a space to make sure it's isolated so the code would be:
for name in keywords:
df[name] = df['description'].apply(lambda x: True if ' '+str(name)+' ' in x else False)
But that's really ugly and not optimised. Regular expression should do the trick but I have to look back into it: found it! [ ]*+[str(name)]+[.?!] is better! (and more appropriate)
One way is to build a regex string to identify any keyword in your string... this example is case insensitive and will find any substring matches - not just whole words...
import pandas as pd
import re
keywords = ['python', 'C++', 'admin', 'Developer']
rx = '(?i)(?P<keywords>{})'.format('|'.join(re.escape(kw) for kw in keywords))
Then with a sample DF of:
df = pd.DataFrame({
'job_description': ['C++ developer', 'traffic warden', 'Python developer', 'linux admin', 'cat herder']
})
You can find all keywords for the relevant column...
matches = df['job_description'].str.extractall(rx)
Which gives:
keyword
match
0 0 C++
1 developer
2 0 Python
1 developer
3 0 admin
Then you want to get a list of "dummies" and take the max (so you always get a 1 where a word was found) using:
dummies = pd.get_dummies(matches).max(level=0)
Which gives:
keyword_C++ keyword_Python keyword_admin keyword_developer
0 1 0 0 1
2 0 1 0 1
3 0 0 1 0
You then left join that back to your original DF:
result = df.join(dummies, how='left')
And the result is:
job_description keyword_C++ keyword_Python keyword_admin keyword_developer
0 C++ developer 1.0 0.0 0.0 1.0
1 traffic warden NaN NaN NaN NaN
2 Python developer 0.0 1.0 0.0 1.0
3 linux admin 0.0 0.0 1.0 0.0
4 cat herder NaN NaN NaN NaN
skill = "C++", or any of the others
frame = an instance of
Index(['job_title', 'company', 'job_label', 'description'],
dtype='object')
jobs = a list/np.array of frames, which is probably your input
A naive implementation could look a bit like this:
for skill in keywords:
for frame in jobs:
if skill in frame["description"]: # or more exact matching, but this is what's in the question
# exists
But you need to put more work into what output structure you are going to use. Just having an output array of 300 columns most of which just contain a False isn't going to be a good plan. I've never worked with Panda's myself, but if it were normal numpy arrays (which panda's DataFrames are under the hood), I would add a column "skills" that can enumerate them.
You can leverage .apply() like so (#Jacco van Dorp made a solid suggestion of storing all of the found skills inside a single column, which I agree is likely the best approach to your problem):
df = pd.DataFrame([['Engineer','Firm','AERO1','Work with python and Django'],
['IT','Dell','ITD4','Work with Django and R'],
['Office Assistant','Dental','OAD3','Coordinate schedules'],
['QA Engineer','Factory','QA2','Work with R and python'],
['Mechanic','Autobody','AERO1','Love the movie Django']],
columns=['job_title','company','job_label','description'])
Which yields:
job_title company job_label description
0 Engineer Firm AERO1 Work with python and Django
1 IT Dell ITD4 Work with Django and R
2 Office Assistant Dental OAD3 Coordinate schedules
3 QA Engineer Factory QA2 Work with R and python
4 Mechanic Autobody AERO1 Love the movie Django
Then define your skill set and your list comprehension to pass to .apply():
skills = ['python','R','Django']
df['skills'] = df.apply(lambda x: [i for i in skills if i in x['description'].split()], axis=1)
Which yields this column:
skills
0 [python, Django]
1 [R, Django]
2 []
3 [python, R]
4 [Django]
If you are still interested in having individual columns for each skill, I can edit my answer to provide that as well.

Output of column in Pandas dataframe from float to currency (negative values)

I have the following data frame (consisting of both negative and positive numbers):
df.head()
Out[39]:
Prices
0 -445.0
1 -2058.0
2 -954.0
3 -520.0
4 -730.0
I am trying to change the 'Prices' column to display as currency when I export it to an Excel spreadsheet. The following command I use works well:
df['Prices'] = df['Prices'].map("${:,.0f}".format)
df.head()
Out[42]:
Prices
0 $-445
1 $-2,058
2 $-954
3 $-520
4 $-730
Now my question here is what would I do if I wanted the output to have the negative signs BEFORE the dollar sign. In the output above, the dollar signs are before the negative signs. I am looking for something like this:
-$445
-$2,058
-$954
-$520
-$730
Please note there are also positive numbers as well.
You can use np.where and test whether the values are negative and if so prepend a negative sign in front of the dollar and cast the series to a string using astype:
In [153]:
df['Prices'] = np.where( df['Prices'] < 0, '-$' + df['Prices'].astype(str).str[1:], '$' + df['Prices'].astype(str))
df['Prices']
Out[153]:
0 -$445.0
1 -$2058.0
2 -$954.0
3 -$520.0
4 -$730.0
Name: Prices, dtype: object
You can use the locale module and the _override_localeconv dict. It's not well documented, but it's a trick I found in another answer that has helped me before.
import pandas as pd
import locale
locale.setlocale( locale.LC_ALL, 'English_United States.1252')
# Made an assumption with that locale. Adjust as appropriate.
locale._override_localeconv = {'n_sign_posn':1}
# Load dataframe into df
df['Prices'] = df['Prices'].map(locale.currency)
This creates a dataframe that looks like this:
Prices
0 -$445.00
1 -$2058.00
2 -$954.00
3 -$520.00
4 -$730.00

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