I create DataFrame
from a list of dicts like this:
pd.DataFrame([{"id":"a","v0":3,"v2":"foo"},
{"id":"b","v1":1,"v4":"ouch"}]).set_index(
"id",verify_integrity=True)
v0 v2 v1 v4
id
a 3.0 foo NaN NaN
b NaN NaN 1.0 ouch
Alas, for some inputs I run out of RAM in the DataFrame
constructor, and I wonder if there is a way to make pandas produce a sparse DataFrame
from the list of dicts.
I suggest to use the dtype='Sparse'
for this.
If all elements are numbers you can use dtype='Sparse'
, dtype='Sparse[int]'
or dtype='Sparse[float]'
data = [{"id":'a',"v0":3,"v2":6},
{"id":'b',"v1":1,"v4":7}]
index = [item.pop('id') for item in data]
pd.DataFrame(data, index=index, dtype="Sparse")
If any value is a string you have to use dtype='Sparse[str]'
.
data = [{"id":'a',"v0":3,"v2":'foo'},
{"id":'b',"v1":1,"v4":'ouch'}]
df = pd.DataFrame(data, dtype="Sparse[str]").set_index("id",verify_integrity=True)