1# https://github.com/ringsaturn/tzfpy/blob/main/examples/tzfpy_with_datetime.py
 2from datetime import datetime, timezone
 3from zoneinfo import ZoneInfo
 4
 5from tzfpy import get_tz
 6
 7tz = get_tz(139.7744, 35.6812)  # Tokyo
 8
 9now = datetime.now(timezone.utc)
10now = now.replace(tzinfo=ZoneInfo(tz))
11print(now)

12025-04-29 01:33:56.325194+09:00

 1# https://github.com/ringsaturn/tzfpy/blob/main/examples/tzfpy_with_arrow.py
 2from zoneinfo import ZoneInfo
 3
 4import arrow
 5from tzfpy import get_tz
 6
 7tz = get_tz(139.7744, 35.6812)  # Tokyo
 8
 9arrow_now = arrow.now(ZoneInfo(tz))
10print(arrow_now)

12025-04-29T10:33:45.551282+09:00

 1# https://github.com/ringsaturn/tzfpy/blob/main/examples/tzfpy_with_whenever.py
 2from tzfpy import get_tz
 3from whenever import Instant
 4
 5now = Instant.now()
 6
 7tz = get_tz(139.7744, 35.6812)  # Tokyo
 8
 9now = now.to_tz(tz)
10
11print(now)

12025-04-29T10:33:28.427784+09:00[Asia/Tokyo]

 1# https://github.com/ringsaturn/tzfpy/blob/main/examples/tzfpy_with_dataframe_pandas.py
 2import time
 3
 4import citiespy
 5import numpy as np
 6import pandas as pd
 7import tzfpy
 8
 9# lazy init
10_ = tzfpy.get_tz(0, 0)
11
12
13cities_as_dict = []
14for city in citiespy.all_cities():
15    cities_as_dict.append({"name": city.name, "lng": city.lng, "lat": city.lat})
16
17df = pd.DataFrame(cities_as_dict)
18
19
20start = time.perf_counter()
21df["tz_from_tzfpy"] = df.apply(lambda x: tzfpy.get_tz(x.lng, x.lat), axis=1)
22end = time.perf_counter()
23print(f"[tzfpy_with_dataframe] Pandas apply Time taken: {end - start} seconds")
24
25vec_tzfpy_get_tz = np.vectorize(tzfpy.get_tz)
26start = time.perf_counter()
27df["tz_from_tzfpy_vec"] = vec_tzfpy_get_tz(df.lng, df.lat)
28end = time.perf_counter()
29print(
30    f"[tzfpy_with_dataframe] Pandas apply with NumPy vectorize Time taken: {end - start} seconds"
31)

1[tzfpy_with_dataframe] Pandas apply Time taken: 0.8276746249757707 seconds
2[tzfpy_with_dataframe] Pandas apply with NumPy vectorize Time taken: 0.348435917054303 seconds

 1import time
 2
 3import citiespy
 4import polars as pl
 5import tzfpy
 6
 7# lazy init
 8_ = tzfpy.get_tz(0, 0)
 9
10
11cities_as_dict = []
12for city in citiespy.all_cities():
13    cities_as_dict.append({"name": city.name, "lng": city.lng, "lat": city.lat})
14
15df = pl.from_dicts(cities_as_dict)
16
17start = time.perf_counter()
18df = df.with_columns(
19    pl.struct(["lng", "lat"])
20    .map_elements(
21        lambda cols: tzfpy.get_tz(cols["lng"], cols["lat"]), return_dtype=pl.Utf8
22    )
23    .alias("tz_from_tzfpy")
24)
25end = time.perf_counter()
26print(f"[tzfpy_with_dataframe] Polars Time taken: {end - start} seconds")

1[tzfpy_with_dataframe] Polars Time taken: 0.34632241702638566 seconds

 1import time
 2
 3import citiespy
 4import numpy as np
 5import pandas as pd
 6import tzfpy
 7
 8# lazy init
 9_ = tzfpy.get_tz(0, 0)
10
11
12cities_as_dict = []
13for city in citiespy.all_cities():
14    cities_as_dict.append({"name": city.name, "lng": city.lng, "lat": city.lat})
15
16df = pd.DataFrame(cities_as_dict)
17
18lngs = df.lng.values
19lats = df.lat.values
20
21vec_tzfpy_get_tz = np.vectorize(tzfpy.get_tz)
22
23start = time.perf_counter()
24_ = vec_tzfpy_get_tz(lngs, lats)
25end = time.perf_counter()
26print(f"[tzfpy_with_dataframe] Numpy Time taken: {end - start} seconds")

1[tzfpy_with_dataframe] Numpy Time taken: 0.33512612502090633 seconds

  1from fastapi import FastAPI, Query
  2from pydantic import BaseModel, Field
  3from tzfpy import data_version, get_tz, get_tzs, timezonenames
  4
  5# lazy init
  6_ = get_tz(0, 0)
  7
  8
  9class TimezoneResponse(BaseModel):
 10    timezone: str = Field(..., description="Timezone", examples=["Asia/Tokyo"])
 11
 12
 13class TimezonesResponse(BaseModel):
 14    timezones: list[str] = Field(
 15        ..., description="Timezones", examples=[["Asia/Shanghai", "Asia/Urumqi"]]
 16    )
 17
 18
 19class TimezonenamesResponse(BaseModel):
 20    timezonenames: list[str] = Field(
 21        ..., description="Timezonenames", examples=[["Etc/GMT+1", "Etc/GMT+2"]]
 22    )
 23
 24
 25class DataVersionResponse(BaseModel):
 26    data_version: str = Field(..., description="Data version", examples=["2025b"])
 27
 28
 29app = FastAPI(
 30    title="tzfpy with FastAPI",
 31    description="tzfpy with FastAPI",
 32    contact={
 33        "name": "tzfpy",
 34        "url": "https://github.com/ringsaturn/tzfpy",
 35    },
 36)
 37
 38
 39@app.get("/")
 40def read_root():
 41    return {"message": "Hello, World!"}
 42
 43
 44@app.get("/timezone", response_model=TimezoneResponse)
 45def get_timezone(
 46    longitude: float = Query(
 47        ...,
 48        description="Longitude",
 49        ge=-180,
 50        le=180,
 51        examples=[139.767125],
 52        openapi_examples={"example-Tokyo": {"value": 139.767125}},
 53    ),
 54    latitude: float = Query(
 55        ...,
 56        description="Latitude",
 57        ge=-90,
 58        le=90,
 59        examples=[35.681236],
 60        openapi_examples={"example-Tokyo": {"value": 35.681236}},
 61    ),
 62):
 63    return TimezoneResponse(timezone=get_tz(longitude, latitude))
 64
 65
 66@app.get("/timezones", response_model=TimezonesResponse)
 67def get_timezones(
 68    longitude: float = Query(
 69        ...,
 70        description="Longitude",
 71        ge=-180,
 72        le=180,
 73        examples=[87.617733],
 74        openapi_examples={"example-Urumqi": {"value": 87.617733}},
 75    ),
 76    latitude: float = Query(
 77        ...,
 78        description="Latitude",
 79        ge=-90,
 80        le=90,
 81        examples=[43.792818],
 82        openapi_examples={"example-Urumqi": {"value": 43.792818}},
 83    ),
 84):
 85    return TimezonesResponse(timezones=get_tzs(longitude, latitude))
 86
 87
 88@app.get("/timezonenames", response_model=TimezonenamesResponse)
 89def get_all_timezones():
 90    return TimezonenamesResponse(timezonenames=timezonenames())
 91
 92
 93@app.get("/data_version", response_model=DataVersionResponse)
 94def get_data_version():
 95    return DataVersionResponse(data_version=data_version())
 96
 97
 98if __name__ == "__main__":
 99    import uvicorn
100
101    uvicorn.run(app, host="0.0.0.0", port=8010)