dd-l2-bangkok-multicrs-audit
Map (reference ← swipe → agent)
0:00
A contractor just shipped `bangkok_contractor_delivery.gpkg` and I need a defect cite-sheet before I sign off. Please walk every layer in the file and write one row per layer to `crs_audit.csv` with these columns: layer_name, declared_crs (formatted as `EPSG:NNNN`), geometry_type, feature_count, sample_x and sample_y for a sample coordinate taken from the layer as it sits on disk, and encoding_detected. For encoding_detected, look at the text attributes for anomalies and report either `latin1-mojibake` or `utf-8`.
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System info
{
"adapter": "openrouter",
"model": "google/gemma-4-26b-a4b-it",
"base_url": "https://openrouter.ai/api/v1"
}
0:01
Bash
ls -l bangkok_contractor_delivery.gpkg
-rw-r--r-- 1 agent agent 2703360 Jun 19 02:42 bangkok_contractor_delivery.gpkg
0:28
Write
/work/solve.py
content · 86 lines · py
import geopandas as gpd
import fiona
import pandas as pd
import csv
def check_encoding(df):
"""
Checks if the text columns in a dataframe contain mojibake.
A simple way is to try to encode/decode or look for specific patterns.
Here we will check if any string column contains characters that look like mojibake.
Specifically, we'll check if strings can be converted from latin-1 to utf-8 without error
but look 'weird', or more simply, if we can detect common mojibake patterns.
Actually, a more robust way is to check if strings contain common replacement characters
or if they were likely read as latin-1 when they were utf-8.
"""
# For the sake of this task, let's see if we can identify latin1-mojibake.
# A common sign of latin1-mojibake is seeing things like 'é' instead of 'é'.
# We'll check all object (string) columns
for col in df.select_dtypes(include=['object']).columns:
for val in df[col].dropna().unique():
if isinstance(val, str):
# Check for patterns like à followed by a character, which is common in utf-8 read as latin-1
# or just try to see if it's "broken"
try:
# If it's valid utf-8 and contains high-bit characters that look like mojibake
# This is a heuristic.
if any(ord(c) > 127 for c in val):
# Try to see if decoding it as latin-1 and re-encoding to utf-8 "fixes" it
# Or if it's already looking like mojibake.
# Let's look for the à pattern specifically.
if 'Ã' in val:
return 'latin1-mojibake'
except:
pass
return 'utf-8'
def audit_gpkg(file_path, output_csv):
layers = fiona.listlayers(file_path)
audit_results = []
for layer in layers:
gdf = gpd.read_file(file_path, layer=layer)
# CRS
if gdf.crs is not None:
declared_crs = f"EPSG:{gdf.crs.to_epsg()}" if gdf.crs.to_epsg() else str(gdf.crs)
else:
declared_crs = "None"
# Geometry Type
if not gdf.empty:
geom_type = gdf.geometry.type.iloc[0]
# Sample coords
sample_row = gdf.iloc[0]
sample_geom = sample_row.geometry
if sample_geom.is_empty:
sample_x, sample_y = None, None
else:
sample_x, sample_y = sample_geom.centroid.x, sample_geom.centroid.y
else:
geom_type = "Unknown"
sample_x, sample_y = None, None
feature_count = len(gdf)
# Encoding detection
encoding = check_encoding(gdf)
audit_results.append({
'layer_name': layer,
'declared_crs': declared_crs,
'geometry_type': geom_type,
'feature_count': feature_count,
'sample_x': sample_x,
'sample_y': sample_y,
'encoding_detected': encoding
})
df_audit = pd.DataFrame(audit_results)
df_audit.to_csv(output_csv, index=False)
print(f"Audit complete. Results written to {output_csv}")
if __name__ == "__main__":
audit_gpkg('bangkok_contractor_delivery.gpkg', 'crs_audit.csv')
Wrote /work/solve.py (3366 chars).
0:30
Bash
python solve.py
Audit complete. Results written to crs_audit.csv
/work/solve.py:20: Pandas4Warning: For backward compatibility, 'str' dtypes are included by select_dtypes when 'object' dtype is specified. This behavior is deprecated and will be removed in a future version. Explicitly pass 'str' to `include` to select them, or to `exclude` to remove them and silence this warning. See https://pandas.pydata.org/docs/user_guide/migration-3-strings.html#string-migration-select-dtypes for details on how to write code that works with pandas 2 and 3. for col in df.select_dtypes(include=['object']).columns: /work/solve.py:20: Pandas4Warning: For backward compatibility, 'str' dtypes are included by select_dtypes when 'object' dtype is specified. This behavior is deprecated and will be removed in a future version. Explicitly pass 'str' to `include` to select them, or to `exclude` to remove them and silence this warning. See https://pandas.pydata.org/docs/user_guide/migration-3-strings.html#string-migration-select-dtypes for details on how to write code that works with pandas 2 and 3. for col in df.select_dtypes(include=['object']).columns: /work/solve.py:20: Pandas4Warning: For backward compatibility, 'str' dtypes are included by select_dtypes when 'object' dtype is specified. This behavior is deprecated and will be removed in a future version. Explicitly pass 'str' to `include` to select them, or to `exclude` to remove them and silence this warning. See https://pandas.pydata.org/docs/user_guide/migration-3-strings.html#string-migration-select-dtypes for details on how to write code that works with pandas 2 and 3. for col in df.select_dtypes(include=['object']).columns:
0:32
Bash
cat crs_audit.csv
layer_name,declared_crs,geometry_type,feature_count,sample_x,sample_y,encoding_detected parcels,EPSG:24047,Polygon,4000,657706.4571303247,1509274.702150785,utf-8 roads,EPSG:32647,LineString,5000,656996.3371533038,1509487.963830215,utf-8 markets,EPSG:4326,Point,1000,100.4533,13.655000000000001,utf-8
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Write
/work/solve.py
content · 69 lines · py
import geopandas as gpd
import fiona
import pandas as pd
def check_encoding(df):
"""
Checks if the text columns in a dataframe contain mojibake.
We'll look for common patterns like 'Ã' which often appears when UTF-8 is read as Latin-1.
"""
for col in df.select_dtypes(include=['object']).columns:
for val in df[col].dropna().unique():
if isinstance(val, str):
# Heuristic: check for the common 'Ã' pattern or other typical mojibake indicators
# Specifically, the presence of multiple high-bit chars that look like broken UTF-8
if 'Ã' in val:
return 'latin1-mojibake'
return 'utf-8'
def audit_gpkg(file_path, output_csv):
layers = fiona.listlayers(file_path)
audit_results = []
for layer in layers:
gdf = gpd.read_file(file_path, layer=layer)
# CRS
if gdf.crs is not None:
epsg = gdf.crs.to_epsg()
declared_crs = f"EPSG:{epsg}" if epsg else str(gdf.crs)
else:
declared_crs = "None"
# Geometry Type
if not gdf.empty:
geom_type = gdf.geometry.type.iloc[0]
# Sample coords: Take the centroid of the first geometry
sample_row = gdf.iloc[0]
sample_geom = sample_row.geometry
if sample_geom.is_empty:
sample_x, sample_y = None, None
else:
# Using centroid to get a representative point for the sample
sample_x, sample_y = sample_geom.centroid.x, sample_geom.centroid.y
else:
geom_type = "Unknown"
sample_x, sample_y = None, None
feature_count = len(gdf)
# Encoding detection
encoding = check_encoding(gdf)
audit_results.append({
'layer_name': layer,
'declared_crs': declared_crs,
'geometry_type': geom_type,
'feature_count': feature_count,
'sample_x': sample_x,
'sample_y': sample_y,
'encoding_detected': encoding
})
df_audit = pd.DataFrame(audit_results)
df_audit.to_csv(output_csv, index=False)
print(f"Audit complete. Results written to {output_csv}")
if __name__ == "__main__":
audit_gpkg('bangkok_contractor_delivery.gpkg', 'crs_audit.csv')
Wrote /work/solve.py (2385 chars).
1:06
Bash
# First, let's check if there's actually any mojibake in the file by looking at ...
# First, let's check if there's actually any mojibake in the file by looking at the content manually if possible.
# Since I can't "look" at the content easily without a script, I'll write a script to check all layers more aggressively.
cat << 'EOF' > /work/check_mojibake.py
import geopandas as gpd
import fiona
def check_mojibake_aggressive(gdf):
for col in gdf.select_dtypes(include=['object']).columns:
for val in gdf[col].dropna().unique():
if isinstance(val, str):
# Looking for common mojibake patterns.
# A very common one is 'Ã' followed by another char
# such as é for é.
import re
if re.search(r'Ã[^\s]', val):
return True
return False
layers = fiona.listlayers('bangkok_contractor_delivery.gpkg')
for layer in layers:
gdf = gpd.read_file('bangkok_contractor_delivery.gpkg', layer=layer)
if check_mojibake_aggressive(gdf):
print(f"Found mojibake in layer: {layer}")
else:
print(f"No mojibake found in layer: {layer}")
EOF
python /work/check_mojibake.py
No mojibake found in layer: parcels No mojibake found in layer: roads No mojibake found in layer: markets
/work/check_mojibake.py:5: Pandas4Warning: For backward compatibility, 'str' dtypes are included by select_dtypes when 'object' dtype is specified. This behavior is deprecated and will be removed in a future version. Explicitly pass 'str' to `include` to select them, or to `exclude` to remove them and silence this warning. See https://pandas.pydata.org/docs/user_guide/migration-3-strings.html#string-migration-select-dtypes for details on how to write code that works with pandas 2 and 3. for col in gdf.select_dtypes(include=['object']).columns: /work/check_mojibake.py:5: Pandas4Warning: For backward compatibility, 'str' dtypes are included by select_dtypes when 'object' dtype is specified. This behavior is deprecated and will be removed in a future version. Explicitly pass 'str' to `include` to select them, or to `exclude` to remove them and silence this warning. See https://pandas.pydata.org/docs/user_guide/migration-3-strings.html#string-migration-select-dtypes for details on how to write code that works with pandas 2 and 3. for col in gdf.select_dtypes(include=['object']).columns: /work/check_mojibake.py:5: Pandas4Warning: For backward compatibility, 'str' dtypes are included by select_dtypes when 'object' dtype is specified. This behavior is deprecated and will be removed in a future version. Explicitly pass 'str' to `include` to select them, or to `exclude` to remove them and silence this warning. See https://pandas.pydata.org/docs/user_guide/migration-3-strings.html#string-migration-select-dtypes for details on how to write code that works with pandas 2 and 3. for col in gdf.select_dtypes(include=['object']).columns:
1:21
Bash
# Let's check the data for "roads" or "parcels" for any non-ASCII.
# Let's check the data for "roads" or "parcels" for any non-ASCII.
# Maybe there is something else.
cat << 'EOF' > /work/inspect_data.py
import geopandas as gpd
layers = ['parcels', 'roads', 'markets']
for layer in layers:
gdf = gpd.read_file('bangkok_contractor_delivery.gpkg', layer=layer)
print(f"Layer: {layer}")
for col in gdf.select_dtypes(include=['object']).columns:
print(f" Column: {col}")
for val in gdf[col].dropna().unique()[:5]:
print(f" {val}")
# Check for characters > 127
if any(ord(c) > 127 for c in str(val)):
print(" !!! Non-ASCII detected !!!")
EOF
python /work/inspect_data.py
Layer: parcels
Column: id
P00000
P00001
P00002
P00003
P00004
Column: name_th
à¹à¸à¸¥à¸à¸à¸µà¹à¸à¸´à¸ à¸à¸²à¸à¸£à¸±à¸
!!! Non-ASCII detected !!!
à¹à¸à¸¥à¸à¸à¸µà¹à¸à¸´à¸ à¸à¸à¸¸à¸¡à¸§à¸±à¸
!!! Non-ASCII detected !!!
à¹à¸à¸¥à¸à¸à¸µà¹à¸à¸´à¸ วัà¸à¸à¸²
!!! Non-ASCII detected !!!
à¹à¸à¸¥à¸à¸à¸µà¹à¸à¸´à¸ à¸à¸¥à¸à¸à¹à¸à¸¢
!!! Non-ASCII detected !!!
à¹à¸à¸¥à¸à¸à¸µà¹à¸à¸´à¸ à¸à¸´à¸à¹à¸à¸
!!! Non-ASCII detected !!!
Column: owner_class
private
state
religious
Layer: roads
Column: id
R00000
R00001
R00002
R00003
R00004
Column: name
à¸à¸à¸à¸ªà¸¸à¸à¸¸à¸¡à¸§à¸´à¸
!!! Non-ASCII detected !!!
à¸à¸à¸à¸à¸£à¸°à¸£à¸²à¸¡ 4
!!! Non-ASCII detected !!!
à¸à¸à¸à¸à¸£à¸°à¸£à¸²à¸¡ 9
!!! Non-ASCII detected !!!
à¸à¸à¸à¸£à¸±à¸à¸à¸²à¸ ิà¹à¸©à¸
!!! Non-ASCII detected !!!
à¸à¸à¸à¹à¸à¸à¸£à¸à¸¸à¸£à¸µ
!!! Non-ASCII detected !!!
Column: highway
primary
secondary
tertiary
residential
service
Layer: markets
Column: id
M00000
M00001
M00002
M00003
M00004
Column: name_th
ตลาดนัดจตุจักร
!!! Non-ASCII detected !!!
ตลาดอ.ต.ก.
!!! Non-ASCII detected !!!
ตลาดคลองเตย
!!! Non-ASCII detected !!!
ตลาดสะพานขาว
!!! Non-ASCII detected !!!
ตลาดบางรัก
!!! Non-ASCII detected !!!
Column: kind
fresh
wet
night
/work/inspect_data.py:7: Pandas4Warning: For backward compatibility, 'str' dtypes are included by select_dtypes when 'object' dtype is specified. This behavior is deprecated and will be removed in a future version. Explicitly pass 'str' to `include` to select them, or to `exclude` to remove them and silence this warning. See https://pandas.pydata.org/docs/user_guide/migration-3-strings.html#string-migration-select-dtypes for details on how to write code that works with pandas 2 and 3. for col in gdf.select_dtypes(include=['object']).columns: /work/inspect_data.py:7: Pandas4Warning: For backward compatibility, 'str' dtypes are included by select_dtypes when 'object' dtype is specified. This behavior is deprecated and will be removed in a future version. Explicitly pass 'str' to `include` to select them, or to `exclude` to remove them and silence this warning. See https://pandas.pydata.org/docs/user_guide/migration-3-strings.html#string-migration-select-dtypes for details on how to write code that works with pandas 2 and 3. for col in gdf.select_dtypes(include=['object']).columns: /work/inspect_data.py:7: Pandas4Warning: For backward compatibility, 'str' dtypes are included by select_dtypes when 'object' dtype is specified. This behavior is deprecated and will be removed in a future version. Explicitly pass 'str' to `include` to select them, or to `exclude` to remove them and silence this warning. See https://pandas.pydata.org/docs/user_guide/migration-3-strings.html#string-migration-select-dtypes for details on how to write code that works with pandas 2 and 3. for col in gdf.select_dtypes(include=['object']).columns:
1:37
Write
/work/solve.py
content · 72 lines · py
import geopandas as gpd
import fiona
import pandas as pd
import re
def check_encoding(df):
"""
Checks if the text columns in a dataframe contain mojibake.
In the parcels and roads layers, we saw characters like 'à¹à¸à¸¥à¸à¸à¸µà¹à¸à¸´à¸'.
This is a classic sign of UTF-8 bytes being interpreted as Latin-1.
"""
for col in df.select_dtypes(include=['object']).columns:
for val in df[col].dropna().unique():
if isinstance(val, str):
# Check for common mojibake patterns.
# Patterns like 'à' followed by other accented characters
# are very common when UTF-8 is read as Latin-1.
# We'll check for the specific pattern seen in the inspection.
if re.search(r'à[^\x00-\x7F]', val):
return 'latin1-mojibake'
return 'utf-8'
def audit_gpkg(file_path, output_csv):
layers = fiona.listlayers(file_path)
audit_results = []
for layer in layers:
gdf = gpd.read_file(file_path, layer=layer)
# CRS
if gdf.crs is not None:
epsg = gdf.crs.to_epsg()
declared_crs = f"EPSG:{epsg}" if epsg else str(gdf.crs)
else:
declared_crs = "None"
# Geometry Type
if not gdf.empty:
geom_type = gdf.geometry.type.iloc[0]
# Sample coords: Take the centroid of the first geometry
sample_row = gdf.iloc[0]
sample_geom = sample_row.geometry
if sample_geom.is_empty:
sample_x, sample_y = None, None
else:
sample_x, sample_y = sample_geom.centroid.x, sample_geom.centroid.y
else:
geom_type = "Unknown"
sample_x, sample_y = None, None
feature_count = len(gdf)
# Encoding detection
encoding = check_encoding(gdf)
audit_results.append({
'layer_name': layer,
'declared_crs': declared_crs,
'geometry_type': geom_type,
'feature_count': feature_count,
'sample_x': sample_x,
'sample_y': sample_y,
'encoding_detected': encoding
})
df_audit = pd.DataFrame(audit_results)
df_audit.to_csv(output_csv, index=False)
print(f"Audit complete. Results written to {output_csv}")
if __name__ == "__main__":
audit_gpkg('bangkok_contractor_delivery.gpkg', 'crs_audit.csv')
Wrote /work/solve.py (2485 chars).
1:38
Bash
python solve.py
Audit complete. Results written to crs_audit.csv
/work/solve.py:12: Pandas4Warning: For backward compatibility, 'str' dtypes are included by select_dtypes when 'object' dtype is specified. This behavior is deprecated and will be removed in a future version. Explicitly pass 'str' to `include` to select them, or to `exclude` to remove them and silence this warning. See https://pandas.pydata.org/docs/user_guide/migration-3-strings.html#string-migration-select-dtypes for details on how to write code that works with pandas 2 and 3. for col in df.select_dtypes(include=['object']).columns: /work/solve.py:12: Pandas4Warning: For backward compatibility, 'str' dtypes are included by select_dtypes when 'object' dtype is specified. This behavior is deprecated and will be removed in a future version. Explicitly pass 'str' to `include` to select them, or to `exclude` to remove them and silence this warning. See https://pandas.pydata.org/docs/user_guide/migration-3-strings.html#string-migration-select-dtypes for details on how to write code that works with pandas 2 and 3. for col in df.select_dtypes(include=['object']).columns: /work/solve.py:12: Pandas4Warning: For backward compatibility, 'str' dtypes are included by select_dtypes when 'object' dtype is specified. This behavior is deprecated and will be removed in a future version. Explicitly pass 'str' to `include` to select them, or to `exclude` to remove them and silence this warning. See https://pandas.pydata.org/docs/user_guide/migration-3-strings.html#string-migration-select-dtypes for details on how to write code that works with pandas 2 and 3. for col in df.select_dtypes(include=['object']).columns:
1:41
Bash
cat crs_audit.csv
layer_name,declared_crs,geometry_type,feature_count,sample_x,sample_y,encoding_detected parcels,EPSG:24047,Polygon,4000,657706.4571303247,1509274.702150785,latin1-mojibake roads,EPSG:32647,LineString,5000,656996.3371533038,1509487.963830215,latin1-mojibake markets,EPSG:4326,Point,1000,100.4533,13.655000000000001,utf-8
1:50