TeruakiUeda / faster_reduce_mem_usage

reduce_mem_usageを早くしたい

Comparison of the two methods

• base code (overwrite)

if c_min > np.iinfo(np.int8).min and c_max < np.iinfo(np.int8).max:
    df[col] = df[col].astype(np.int8)

• change (concat)

dfs = []
...
if c_min > np.iinfo(np.int8).min and c_max < np.iinfo(np.int8).max:
    dfs.append(df[col].astype(np.int8))
...
df_out = pd.concat(dfs, axis=1)

• result