What I want to do was actually group by all similar strings in one columns and sum their
corresponding counts if there are similarity, otherwise, leave them.
A little similar to this post. Unfortunately I have not been able to apply this to my case:
How to group Pandas data frame by column with regex match
Unfortunately, I ended up with the following steps:
I wrote a function to print out all the fuzz.Wratio for each row of string,
when each row does a linear search from the top to check if there are other similar
strings in the rest of the rows. If the WRatio > 90, I would like to sum these row's
corresponding counts. Otherwise, leave them there.
I created a test data looking like this:
test_data=pd.DataFrame({
'name':['Apple.Inc.','apple.inc','APPLE.INC','OMEGA'],
'count':[4,3,2,6]
})
So what I want to do is make the result as a dataframe like:
result=pd.Dataframe({
'Nname':['Apple.Inc.','OMEGA'],
'Ncount':[9,6]
})
My function so far only gave me the fuzz ratio for each row,
and to my understanding is that,
each row compares to itself three times( here we have four rows).
So My function output would look like:
pd.Dataframe({
'Nname':['Apple.Inc.','Apple.Inc.','Apple.Inc.','apple.inc',\
'apple.inc','apple.inc'],
'Ncount':[4,4,4,3,3,3],
'FRatio': [100,100,100,100,100,100] })
This is just one portion of the whole output from the function I wrote with this test data.
And the last row "OMEGA" would give me a fuzz ratio about 18.
My function is like this:
def checkDupTitle2(data):
Nname=[]
Ncount=[]
f_ratio=[]
for i in range(0, len(data)):
current=0
count=0
space=0
for space in range(0, len(data)-1-current):
ratio=fuzz.WRatio(str(data.loc[i]['name']).strip(), \
str(data.loc[current+space]['name']).strip())
Nname.append(str(data.loc[i]['name']).strip())
Ncount.append(str(data.loc[i]['count']).strip())
f_ratio.append(ratio)
df=pd.DataFrame({
'Nname': Nname,
'Ncount': Ncount,
'FRatio': f_ratio
})
return df
So after running this function and get the output,
I tried to get what I eventually want.
here I tried group by on the df created above:
output.groupby(output.FRatio>90).sum()
But this way, I still need a "name" in my dataframe,
how can I decide on which names for this total counts, say, 9 here.
"Apple.Inc" or "apple.inc" or "APPLE.INC"?
Or, did I make it too complex?
Is there a way to group by "name" at the very first and treat "Apple.Inc.", "apple.inc" and "APPLE.INC" all the same, then my problem has solved. I have stump quite a while. Any helps would be highly
appreciated! Thanks!
The following code is using my library RapidFuzz instead of FuzzyWuzzy since it is faster and it has a process method extractIndices which does help here. This solution is quite a bit faster, but since I do not work with pandas regulary I am sure there are still some things that could be improved :)
import pandas as pd
from rapidfuzz import process, utils
def checkDupTitle(data):
values = data.values.tolist()
companies = [company for company, _ in values]
pcompanies = [utils.default_process(company) for company in companies]
counts = [count for _, count in values]
results = []
while companies:
company = companies.pop(0)
pcompany = pcompanies.pop(0)
count = counts.pop(0)
duplicates = process.extractIndices(
pcompany, pcompanies,
processor=None, score_cutoff=90, limit=None)
for (i, _) in sorted(duplicates, reverse=True):
count += counts.pop(i)
del pcompanies[i]
del companies[i]
results.append([company, count])
return pd.DataFrame(results, columns=['Nname','Ncount'])
test_data=pd.DataFrame({
'name':['Apple.Inc.','apple.inc','APPLE.INC','OMEGA'],
'count':[4,3,2,6]
})
checkDupTitle(test_data)
The result is
pd.Dataframe({
'Nname':['Apple.Inc.','OMEGA'],
'Ncount':[9,6]
})
Related
I'have a Dataframe, that correspond to lat/long of an object in movement.
This object go from one place to another, and I created a column that reference what place he is at every second.
I want to split that dataframe, so when the object go in one place, the leave to another, I'll have two separate dataframe.
'None' mean he is between places
My actual code :
def cut_df2(df):
df_copy = df.copy()
#check if change of place
df_copy['changed'] = df_copy['place'].ne(df_copy['place'].shift().bfill()).astype(int)
last = 0
dfs= []
for num, line in df_copy.iterrows():
if line.changed:
dfs.append(df.iloc[last:num,:])
last = num
# Check if last line was in a place
if line.place != 'None':
dfs.append(df.iloc[last:,:])
df_outs= []
# Delete empty dataframes
for num, dataframe in enumerate(dfs):
if not dataframe.empty :
if dataframe.reset_index().place.iloc[0] != 'None':
df_outs.append(dataframe)
return df_outs
It won't work on big dataset, but work on simple examples and I've no idea why, anyone can help me?
Try using this instead:
https://www.geeksforgeeks.org/split-pandas-dataframe-by-rows/
iloc can be a good way to split a dataframe
df1 = datasX.iloc[:, :72]
df2 = datasX.iloc[:, 72:]
(I've edited the first column name in the labels_df for clarity)
I have two DataFrames, train_df and labels_df. train_df has integers that map to attribute names in the labels_df. I would like to look up each number within a given train_df cell and return in the adjacent cell, the corresponding attribute name from the labels_df.
So fore example, the first observation in train_df has attribute_ids of 147, 616 and 813 which map to (in the labels_df) culture::french, tag::dogs, tag::men. And I would like to place those strings inside one cell on the same row as the corresponding integers.
I've tried variations of the function below but fear I am wayyy off:
def my_mapping(df1, df2):
tags = df1['attribute_ids']
for i in tags.iteritems():
df1['new_col'] = df2.iloc[i]
return df1
The data are originally from two csv files:
train.csv
labels.csv
I tried this from #Danny :
sample_train_df['attribute_ids'].apply(lambda x: [sample_labels_df[sample_labels_df['attribute_name'] == i]
['attribute_id_num'] for i in x])
*please note - I am running the above code on samples of each DF due to run times on the original DFs.
which returned:
I hope this is what you are looking for. i am sure there's a much more efficient way using look up.
df['new_col'] = df['attribute_ids'].apply(lambda x: [labels_df[labels_df['attribute_id'] == i]['attribute_name'] for i in x])
This is super ugly and one day, hopefully sooner than later, i'll be able to accomplish this task in an elegant fashion though, until then, this is what got me the result I need.
split train_df['attribute_ids'] into their own cell/column
helper_df = train_df['attribute_ids'].str.split(expand=True)
combine train_df with the helper_df so I have the id column (they are photo id's)
train_df2 = pd.concat([train_df, helper_df], axis=1)
drop the original attribute_ids column
train_df2.drop(columns = 'attribute_ids', inplace=True)
rename the new columns
train_df2.rename(columns = {0:'attr1', 1:'attr2', 2:'attr3', 3:'attr4', 4:'attr5', 5:'attr6',
6:'attr7', 7:'attr8', 8:'attr9', 9:'attr10', 10:'attr11'})
convert the labels_df into a dictionary
def create_file_mapping(df):
mapping = dict()
for i in range(len(df)):
name, tags = df['attribute_id_num'][i], df['attribute_name'][i]
mapping[str(name)] = tags
return mapping
map and replace the tag numbers with their corresponding tag names
train_df3 = train_df2.applymap(lambda s: my_map.get(s) if s in my_map else s)
create a new column of the observations tags in a list of concatenated values
helper1['new_col'] = helper1[helper1.columns[0:10]].apply(lambda x: ','.join(x.astype(str)), axis = 1)
I have some data 33k rows x 57 columns.
In some columns there is a data which I want to translate with dictionary.
I have done translation, but now I want to write back translated data to my data set.
I have problem with saving tuples output from for loop.
I am using tuples for creating good translation. .join and .append is not working in my case. I was trying in many case but without any success.
Looking for any advice.
data = pd.read_csv(filepath, engine="python", sep=";", keep_default_na=False)
for index, row in data.iterrows():
row["translated"] = (tuple(slownik.get(znak) for znak in row["1st_service"]))
I just want to see in print(data["1st_service"] a translated data not the previous one before for loop.
First of all, if your csv doesn't already have a 'translated' column, you'll have to add it:
import numpy as np
data['translated'] = np.nan
The problem is the row object you're trying to write to is only a view of the dataframe, it's not the dataframe itself. Plus you're missing square brackets for your list comprehension, if I'm understanding what you're doing. So change your last line to:
data.loc[index, "translated"] = tuple([slownik.get(znak) for znak in row["1st_service"]])
and you'll get a tuple written into that one cell.
In future, posting the exact error message you're getting is very helpful!
I have manage it, below working code:
data = pd.read_csv(filepath, engine="python", sep=";", keep_default_na=False)
data.columns = []
slownik = dict([ ])
trans = ' '
for index, row in data.iterrows():
trans += str(tuple([slownik.get(znak) for znak in row["1st_service"]]))
data['1st_service'] = trans.split(')(')
data.to_csv("out.csv", index=False)
Can you tell me if it is well done?
Maybe there is an faster way to do it?
I am doing it for 12 columns in one for loop, as shown up.
I have a DataFrame with a column named 'UserNbr' and a column named 'Spclty', which is composed of elements like this:
[['104', '2010-01-31'], ['215', '2014-11-21'], ['352', '2016-07-13']]
where there can be 0 or more elements in the list.
Some UserNbr keys appear in multiple rows, and I wish to collapse each such group into a single row such that 'Spclty' contains all the unique dicts like those in the list shown above.
To save overhead on appending to a DataFrame, I'm appending each output row to a list, instead to the DataFrame.
My code is working, but it's taking hours to run on 0.7M rows of input. (Actually, I've never been able to keep my laptop open long enough for it to finish executing.)
Is there a better way to aggregate into a structure like this, maybe using a library that provides more data reshaping options instead looping over UserNbr? (In R, I'd use the data.table and dplyr libraries.)
# loop over all UserNbr:
# consolidate specialty fields into dict-like sets (to remove redundant codes);
# output one row per user to new data frame
out_rows = list()
spcltycol = df_tmp.column.get_loc('Spclty')
all_UserNbr = df_tmp['UserNbr'].unique()
for user in all_UserNbr:
df_user = df_tmp.loc[df_tmp['UserNbr'] == user]
if df_user.shape[0] > 0:
open_combined = df_user_open.iloc[0, spcltycol] # capture 1st row
for row in range(1, df_user.shape[0]): # union with any subsequent rows
open_combined = open_combined.union(df_user.iloc[row, spcltycol])
new_row = df_user.drop(['Spclty', 'StartDt'], axis = 1).iloc[0].tolist()
new_row.append(open_combined)
out_rows.append(new_row)
# construct new dataframe with no redundant UserID rows:
df_out = pd.DataFrame(out_rows,
columns = ['UserNbr', 'Spclty'])
# convert Spclty sets to dicts:
df_out['Spclty'] = [dict(df_out['Spclty'][row]) for row in range(df_out.shape[0])]
The conversion to dict gets rid of specialties that are repeated between rows, In the output, a Spclty value should look like this:
{'104': '2010-01-31', '215': '2014-11-21', '352': '2016-07-13'}
except that there may be more key-value pairs than in any corresponding input row (resulting from aggregation over UserNbr).
I withdraw this question.
I had hoped there was an efficient way to use groupby with something else, but I haven't found any examples with a complex data structure like this one and have received no guidance.
For anyone who gets similarly stuck with very slow aggregation problems in Python, I suggest stepping up to PySpark. I am now tackling this problem with a Databricks notebook and am making headway with the pyspark.sql.window Window functions. (Now, it only takes minutes to run a test instead of hours!)
A partial solution is in the answer here:
PySpark list() in withColumn() only works once, then AssertionError: col should be Column
I'm trying to build a data-frame of time series data. I have to retrieve the data from an API and every (i,j) entry in the data-frame (where "i" is the row and "j" is the column) has to be iterated through and filled individually.
Here's an idea of the type of thing i'm trying to do (note the API i'm using doesn't have historical data for what i'm trying to analyze):
import pandas as pd
import numpy as np
import time
def retrievedata(string):
take string
do some stuff with api
return float
label_list = ['label1','label1','label1', etc...]
discrete_points = 720
df = pd.DataFrame(index=np.arange(0, discrete_points), columns=(i for i in label_list))
So at this point I've pre-allocated a data frame. What comes next is the issue.
Now, I want to iterate over it and assign values to every (i,j) entry in the data frame based on a function i wrote to pull data. Note that the function I wrote has to be specific to a certain column (as it is taking as input the column label). And on top of that, each row will have different values b/c it is time-series data.
EDIT: Yuck, I found a gross way to make it work:
for row in range(discrete_points):
for label in label_list:
df.at[row, label] = retrievedata(label)
This is obviously a non-pythonic, non-numpy, non-pandas way of doing things. So i'd like to find a nicer and more efficient/less computing power intensive way of doing this.
I'm assuming it's gonna have to be some combination of: iter.rows(); iter.tuples(); df.loc(); df.at()
I'm stumped though.
Any ideas?