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SQLBot/backend/apps/datasource/utils/excel.py
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Python

from decimal import Decimal, InvalidOperation, ROUND_HALF_UP
import pandas as pd
FIELD_TYPE_MAP = {
'int64': 'int',
'int32': 'int',
'float64': 'float',
'float32': 'float',
'datetime64': 'datetime',
'datetime64[ns]': 'datetime',
'object': 'string',
'string': 'string',
'bool': 'string',
}
USER_TYPE_TO_PANDAS = {
'int': 'int64',
'float': 'float64',
'datetime': 'datetime64[ns]',
'string': 'string',
}
def infer_field_type(dtype) -> str:
dtype_str = str(dtype)
return FIELD_TYPE_MAP.get(dtype_str, 'string')
def _round_import_integer(value):
"""Round explicitly selected integer values without a float intermediate."""
if pd.isna(value) or (isinstance(value, str) and not value.strip()):
return pd.NA
if isinstance(value, bool):
return int(value)
try:
number = Decimal(str(value))
except InvalidOperation as exc:
raise ValueError('Invalid numeric value for integer field') from exc
if not number.is_finite():
raise ValueError('Integer fields require finite numeric values')
rounded = number.to_integral_value(rounding=ROUND_HALF_UP)
if rounded < -(2 ** 63) or rounded > 2 ** 63 - 1:
raise ValueError('Rounded value is outside the signed 64-bit integer range')
return int(rounded)
def read_import_dataframe(save_path: str, sheet_name: str, field_mapping: dict):
"""Read stored cell values; round only columns explicitly selected as integers."""
dtype_dict = {
column: 'object' if field_type == 'int' else USER_TYPE_TO_PANDAS.get(field_type, 'string')
for column, field_type in field_mapping.items()
}
if save_path.endswith('.csv'):
df = pd.read_csv(save_path, engine='c', dtype=dtype_dict)
else:
df = pd.read_excel(save_path, sheet_name=sheet_name, engine='calamine', dtype=dtype_dict)
for column, field_type in field_mapping.items():
if field_type == 'int' and column in df.columns:
try:
# Build a nullable integer array directly: Series.map can coerce
# large integers plus missing values to lossy float64 values.
df[column] = pd.array([_round_import_integer(value) for value in df[column]], dtype='Int64')
except ValueError as exc:
raise ValueError(f"Column '{column}': {exc}") from exc
return df
def parse_excel_preview(save_path: str, max_rows: int = 10):
sheets_data = []
if save_path.endswith(".csv"):
df = pd.read_csv(save_path, engine='c')
fields = []
for col in df.columns:
fields.append({
"fieldName": col,
"fieldType": infer_field_type(df[col].dtype)
})
preview_df = df.head(max_rows).replace({pd.NA: None, float('nan'): None})
preview_data = preview_df.to_dict(orient='records')
sheets_data.append({
"sheetName": "Sheet1",
"fields": fields,
"data": preview_data,
"rows": len(df)
})
else:
sheet_names = pd.ExcelFile(save_path).sheet_names
for sheet_name in sheet_names:
df = pd.read_excel(save_path, sheet_name=sheet_name, engine='calamine')
fields = []
for col in df.columns:
fields.append({
"fieldName": col,
"fieldType": infer_field_type(df[col].dtype)
})
preview_df = df.head(max_rows).replace({pd.NA: None, float('nan'): None})
preview_data = preview_df.to_dict(orient='records')
sheets_data.append({
"sheetName": sheet_name,
"fields": fields,
"data": preview_data,
"rows": len(df)
})
return sheets_data