I want to get data from only df2 (all columns) by comparing 'no' filed in both df1 and df2.
My 3 line code is below, for this i'm getting all columns from df1 and df2 not able to trim fields from df1. How to achieve ?
I've 2 pandas dataframes like below :
df1:
no,name,salary
1,abc,100
2,def,105
3,abc,110
4,def,115
5,abc,120
df2:
no,name,salary,dept,addr
1,abc,100,IT1,ADDR1
2,abc,101,IT2,ADDR2
3,abc,102,IT3,ADDR3
4,abc,103,IT4,ADDR4
5,abc,104,IT5,ADDR5
6,abc,105,IT6,ADDR6
7,abc,106,IT7,ADDR7
8,abc,107,IT8,ADDR8
df1 = pd.read_csv("D:\\data\\data1.csv")
df2 = pd.read_csv("D:\\data\\data2.csv")
resDF = pd.merge(df1, df2, on='no' , how='inner')
I think you need filter only no column, then on and how parameters are not necessary:
resDF = pd.merge(df1[['no']], df2)
Or use boolean indexing with filtering by isin:
resDF = df2[df2['no'].isin(df1['no'])]
Related
I have a client data df with 200+ columns, say A,B,C,D...X,Y,Z. There's a column in this df which has CAMPAIGN_ID in it. I have another data mapping_csv that has CAMPAIGN_ID and set of columns I need from df. I need to split df into one csv file for each campaign, that will have rows from that campaign and only those columns that are as per mapping_csv.
I am getting type error as below.
TypeError: unhashable type: 'list'
This is what I tried.
for campaign in df['CAMPAIGN_ID'].unique():
df2 = df[df['CAMPAIGN_ID']==campaign]
# remove blank columns
df2.dropna(how='all', axis=1, inplace=True)
for column in df2.columns:
if df2[column].unique()[0]=="0000-00-00" and df2[column].unique().shape[0]==1:
df2 = df2.drop(column, axis=1)
for column in df2.columns:
if df2[column].unique()[0]=='0' and df2[column].unique().shape[0]==1:
df2 = df2.drop(column, axis=1)
# select required columns
df2 = df2[mapping_csv.loc[mapping_csv['CAMPAIGN_ID']==campaign, 'Variable_List'].str.replace(" ","").str.split(",")]
file_shape = df2.shape[0]
filename = "cart_"+str(dt.date.today().strftime('%Y%m%d'))+"_"+campaign+"_rowcnt_"+str(file_shape)
df2.to_csv(filename+".csv",index=False)
Any help will be appreciated.
This is how data looks like -
This is how mapping looks like -
This addresses your core problem.
df = pd.DataFrame(dict(id=['foo','foo','bar','bar',],a=[1,2,3,4,], b=[5,6,7,8], c=[1,2,3,4]))
mapper = dict(foo=['a','b'], bar=['b','c'])
for each_id in df.id.unique():
df_id = df.query(f'id.str.contains("{each_id}")').loc[:,mapper[each_id]]
print(df_id)
I have two dfs:- df1 and df2.:-
dfs=[df1,df2]
df_final = reduce(lambda left,right: pd.merge(left,right,on='Serial_Nbr'), dfs)
I want to select only one column apart from the merge column Serial_Nbr in df1while doing the merge.
how do i do this..?
Filter column in df1:
dfs=[df1[['Serial_Nbr']],df2]
Or if only 2 DataFrames remove reduce:
df_final = pd.merge(df1[['Serial_Nbr']], df2, on='Serial_Nbr')
I have 2 DataFrames : df0 and df1 and df1.shape[0] > df1.shape[0].
df0 and df1 have the exact same columns.
Most of the rows of df0 are in df1.
The indices of df0 and df1 are
df0.index = range(df0.shape[0])
df1.index = range(df1.shape[0])
I then created dft
dft = pd.concat([df0, df1], axis=0, sort=False)
and removed duplicated rows with
dft.drop_duplicates(subset='this_col_is_not_index', keep='first', inplace=True)
I have some duplicates on the index of dft. For example :
dft.loc[3].shape
returns
(2, 38)
My aim is to change the index of the second row returned to have a unique index 3.
This second row should be indexed dft.index.sort_values()[-1]+1.
I would like to apply this operation on all duplicates.
References :
Python Pandas: Get index of rows which column matches certain value
Pandas: Get duplicated indexes
Redefining the Index in a Pandas DataFrame object
Add parameter ignore_index=True to concat for avoid duplicated index values:
dft = pd.concat([df0, df1], axis=0, sort=False, ignore_index=True)
Use reset_index(drop = True)
dft.reset_index(drop=True)
I have two dataframe df1 and df2, in df1 I have 'id', 'name', 'rol' and in df2 I have 'id', 'sal', 'add', 'deg'.
I have to merge only 'sal' and 'deg' column from df2 to df1.
I have successfully merged all columns from df2 to df1.
but now I just need to add two columns on the basis of common column "id"
I am using python 3.7 version.
df_right = pd.merge(df1,df2,how='right',on='id')
how can I merge only these two columns ('sal' and 'deg') from df2 on the basis of 'id'?
Just go slice before you merge like so.
pd.merge(left=df1, right=df2[['id', 'sal', 'deg']], how='right', on='id')
I have several dataframes that I have concatenated with pandas in the line:
xspc = pd.concat([df1,df2,df3], axis = 1, join_axes = [df3.index])
In df2 the index values read one day later than the values of df1, and df3. So for instance when the most current date is 7/1/19 the index values for df1 and df3 will read "7/1/19" while df2 reads '7/2/19'. I would like to be able to concatenate each series so that each dataframe is joined on the most recent date, so in other words I would like all the dataframe values from df1 index value '7/1/19' to be concatenated with dataframe 2 index value '7/2/19' and dataframe 3 index value '7/1/19'. When methods can I use to shift the data around to join on these not matching index values?
You can reset the index of the data frame and then concat the dataframes
df1=df1.reset_index()
df2=df2.reset_index()
df3=df3.reset_index()
df_final = pd.concat([df1,df2,df3],axis=1, join_axes=[df3.index])
This should work since you mentioned that the date in df2 will be one day after df1 or df3