Python 将 DataFrame 列类型从字符串转换为日期时间，dd/mm/yyyy 格式
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Convert DataFrame column type from string to datetime, dd/mm/yyyy format
提问by perigee
How can I convert a DataFrame column of strings (in dd/mm/yyyyformat) to datetimes?
如何将字符串的 DataFrame 列（以dd/mm/yyyy格式）转换为日期时间？
采纳答案by Andy Hayden
The easiest way is to use to_datetime:
最简单的方法是使用to_datetime：
df['col'] = pd.to_datetime(df['col'])
It also offers a dayfirstargument for European times (but beware this isn't strict).
它还dayfirst为欧洲时代提供了一个论据（但要注意这不是严格的）。
Here it is in action:
这是在行动：
In [11]: pd.to_datetime(pd.Series(['05/23/2005']))
Out[11]:
0 2005-05-23 00:00:00
dtype: datetime64[ns]
You can pass a specific format:
您可以传递特定格式：
In [12]: pd.to_datetime(pd.Series(['05/23/2005']), format="%m/%d/%Y")
Out[12]:
0 2005-05-23
dtype: datetime64[ns]
回答by sigurdb
If your date column is a string of the format '2017-01-01' you can use pandas astype to convert it to datetime.
如果您的日期列是格式为“2017-01-01”的字符串，您可以使用 pandas astype 将其转换为日期时间。
df['date'] = df['date'].astype('datetime64[ns]')
df['date'] = df['date'].astype('datetime64[ns]')
or use datetime64[D] if you want Day precision and not nanoseconds
或使用 datetime64[D] 如果您想要 Day 精度而不是纳秒
print(type(df_launath['date'].iloc[0]))
print(type(df_launath['date'].iloc[0]))
yields
产量
<class 'pandas._libs.tslib.Timestamp'>the same as when you use pandas.to_datetime
<class 'pandas._libs.tslib.Timestamp'>与使用 pandas.to_datetime 时相同
You can try it with other formats then '%Y-%m-%d' but at least this works.
您可以尝试使用其他格式然后 '%Y-%m-%d' 但至少这是有效的。
回答by Ekhtiar
You can use the following if you want to specify tricky formats:
如果要指定棘手的格式，可以使用以下内容：
df['date_col'] = pd.to_datetime(df['date_col'], format='%d/%m/%Y')
More details on formathere:
更多细节在format这里：
回答by abhyudayasrinet
If you have a mixture of formats in your date, don't forget to set infer_datetime_format=Trueto make life easier
如果您的约会对象混合了多种格式，请不要忘记设置infer_datetime_format=True让生活更轻松
df['date'] = pd.to_datetime(df['date'], infer_datetime_format=True)
df['date'] = pd.to_datetime(df['date'], infer_datetime_format=True)
Source: pd.to_datetime
or if you want a customized approach:
或者如果你想要一个定制的方法：
def autoconvert_datetime(value):
formats = ['%m/%d/%Y', '%m-%d-%y'] # formats to try
result_format = '%d-%m-%Y' # output format
for dt_format in formats:
try:
dt_obj = datetime.strptime(value, dt_format)
return dt_obj.strftime(result_format)
except Exception as e: # throws exception when format doesn't match
pass
return value # let it be if it doesn't match
df['date'] = df['date'].apply(autoconvert_datetime)
