While assign a new column to my DataFrame I get this error here is my code
def check_header(header, df):
print("Header : ",header)
for item in header:
if not item in df.columns:
df = df.assign(item) #here I'm getting error
return df[header]
I have check this post but din't work for me because my pandas version is satisfying it's
>>> import pandas as pd
>>> pd.__version__
'1.1.5'
what is problem in my code please help me.
If need add new columns by header list with convert not matched values to new columns filled by NaNs use DataFrame.reindex:
df = pd.DataFrame(data = {"test":["mkt1","mkt2","mkt3"],
"test2":["cty1","cty2","cty3"]})
def check_header(header, df):
return df.reindex(header, axis=1)
a = ['test','test1','test3']
print (check_header(a, df))
test test1 test3
0 mkt1 NaN NaN
1 mkt2 NaN NaN
2 mkt3 NaN NaN
If need same values in new columns use fill_value parameter:
def check_header(header, df):
return df.reindex(header, axis=1, fill_value=0)
a = ['test','test1','test3']
print (check_header(a, df))
test test1 test3
0 mkt1 0 0
1 mkt2 0 0
2 mkt3 0 0
If need different values per new column use DataFrame.assign with dictionary for new columns names like keys::
def check_header(header, df):
diff = np.setdiff1d(header, df.columns)
d = dict(zip(diff, diff))
print (d)
{'test1': 'test1', 'test3': 'test3'}
return df.assign(**d).reindex(header, axis=1)
a = ['test','test1','test3']
print (check_header(a, df))
test test1 test3
0 mkt1 test1 test3
1 mkt2 test1 test3
2 mkt3 test1 test3
AttributeError: 'DataFrame' object has no attribute 'reindex'