如何在Python中将时间字符串"20180425.142117"转为人类易读格式？

Got it, let's break down how to turn your timestamp string 20180425.142117 into a friendly format like 25th April 2018, 2:21 pm in Python. Here's a complete, easy-to-follow solution:

Step 1: Parse the Raw Timestamp #

First, we need to convert the string into a datetime object using datetime.strptime(). This function lets us define exactly how the input string is structured so Python can interpret it correctly.

Step 2: Add Ordinal Suffixes (st/nd/rd/th) #

Python's built-in formatting doesn't handle ordinal suffixes automatically, so we'll write a small helper function to generate them correctly—this includes edge cases like 11th, 12th, and 13th, which don't follow the standard digit-to-suffix rule.

Step 3: Format to the Target String #

Once we have the datetime object, we can extract and format each component (day with suffix, month name, year, 12-hour time) into the final human-readable string.

Full Code Example #

from datetime import datetime

def get_ordinal(day):
    """Return the day with its ordinal suffix (e.g., 25 → 25th)"""
    if 11 <= day <= 13:
        return f"{day}th"
    last_digit = day % 10
    suffix_map = {1: "st", 2: "nd", 3: "rd"}
    return f"{day}{suffix_map.get(last_digit, 'th')}"

# Your input timestamp
raw_timestamp = "20180425.142117"

# Parse the string into a datetime object
parsed_dt = datetime.strptime(raw_timestamp, "%Y%m%d.%H%M%S")

# Build the formatted string
ordinal_day = get_ordinal(parsed_dt.day)
# Format time to 12-hour format, removing leading zero from hour
formatted_time = parsed_dt.strftime("%I:%M %p").lstrip('0').lower()

final_result = f"{ordinal_day} {parsed_dt.strftime('%B %Y')}, {formatted_time}"

print(final_result)  # Output: 25th April 2018, 2:21 pm

Key Details: #

• Parsing: The format string "%Y%m%d.%H%M%S" matches your input perfectly: %Y (4-digit year), %m (2-digit month), %d (2-digit day), followed by a dot, then %H (24-hour hour), %M (minutes), %S (seconds).
• Ordinal Suffixes: The helper function first checks for the 11-13 exception, then uses a dictionary to map single digits to their correct suffixes—falling back to "th" for all other cases.
• Time Formatting: %I gives the 12-hour hour (with a leading zero for values 1-9), so we use lstrip('0') to clean that up. The .lower() converts PM to pm to match your example; remove it if you prefer uppercase PM.

内容的提问来源于stack exchange，提问作者AS_ON