Reputation: 151
I am trying to write a pandas dataframe
to parquet
file format in append
mode. However, instead of appending to the existing file, the file is overwritten with new data. What am i missing?
the write syntax is
df.to_parquet(path, mode='append')
the read syntax is
pd.read_parquet(path)
Upvotes: 0
Views: 1553
Reputation: 8694
You will have to use fastparquet engine for this.
import pandas as pd
import os.path
file_path = "D:\\dev\\output.parquet"
df = pd.DataFrame(data={'col1': [1, 2,], 'col2': [3, 4]})
if not os.path.isfile(file_path):
df.to_parquet(file_path, engine='fastparquet')
else:
df.to_parquet(file_path, engine='fastparquet', append=True)
This is described more in this answer here - https://stackoverflow.com/a/74209756/6563567
Upvotes: 3