调用Google Maps API获取路线遇HTTP 400错误（Python Googlemaps库）

Hey there! That HTTP 400 error is definitely tied to your departure_time parameter—let's break down why and how to fix it.

The Google Maps Directions API doesn't accept human-readable date strings like "2018-04-05 09:00:00" for departure_time. Instead, it expects one of two valid formats:

• A UNIX timestamp (integer representing seconds since January 1, 1970 UTC)
• The string "now" for real-time departure calculations

Solution 1: Convert your date string to a UNIX timestamp #

Use Python's built-in datetime and time modules to convert your desired departure time into the correct format. Here's a working example:

from datetime import datetime
import time

# Parse your date string into a datetime object
departure_datetime = datetime.strptime("2018-04-05 09:00:00", "%Y-%m-%d %H:%M:%S")
# Convert to UNIX timestamp (seconds since epoch)
departure_timestamp = int(time.mktime(departure_datetime.timetuple()))

# Updated API call with valid departure_time
directions_result = gmaps.directions(
    IN,
    OUT,
    mode="driving",
    departure_time=departure_timestamp,
    traffic_model='pessimistic',
    alternatives=False,
    language="ja"
)

Solution 2: Handle Time Zones (Critical for Accuracy) #

Since you're using language="ja", your departure time is likely in Japan Standard Time (JST). To avoid UTC conversion errors, explicitly handle time zones with the pytz library:

First, install pytz if you haven't already:

pip install pytz

Then adjust your code to account for the time zone:

from datetime import datetime
import pytz

# Define the Japan time zone
jst_timezone = pytz.timezone('Asia/Tokyo')
# Parse the date string and attach the correct time zone
departure_datetime = jst_timezone.localize(datetime.strptime("2018-04-05 09:00:00", "%Y-%m-%d %H:%M:%S"))
# Convert to UTC-based UNIX timestamp
departure_timestamp = int(departure_datetime.timestamp())

# Final API call with time zone-aware timestamp
directions_result = gmaps.directions(
    IN,
    OUT,
    mode="driving",
    departure_time=departure_timestamp,
    traffic_model='pessimistic',
    alternatives=False,
    language="ja"
)

Why This Works #

HTTP 400 errors for the Google Maps API almost always indicate a malformed request parameter. By switching to the UNIX timestamp format the API explicitly expects, you're providing the exact data it needs to calculate route times with traffic predictions.

内容的提问来源于stack exchange，提问作者user9191983