问题

数据处理需要根据日期过滤，但是读入 dataframe 的日期数据是 Object 类型，无法进行排序和过滤。

解决方法

将 Object 类型的日期字段转换成时间类型，然后再进行过滤、排序等操作

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import pandas as pd
from datetime import datetime, timedelta

# 读取 csv
df = pd.read_csv('test.csv', low_memory=False)
# >>> df
#        id                                              quote         author              date
# 0  656222                 Every moment is a fresh beginning.      T.S Eliot  2020-11-11 11:22
# 1  346927                Everything you can imagine is real.  Pablo Picasso  2020-11-12 12:23
# 2  995443                       Whatever you do, do it well.    Walt Disney  2020-11-13 13:24
# 3  281277                     When words fail, music speaks.    Shakespeare  2020-11-14 14:25
# 4  603115  If God did not exist, it would be necessary to...       Voltaire  2020-11-15 15:26
# 5  605452                        Brevity is the soul of wit.    Shakespeare  2020-11-16 16:27
# >>> df.dtypes
# id         int64
# quote     object
# author    object
# date      object
# dtype: object


# 转换字段类型
df['date'] = pd.to_datetime(df['date'])
df[['quote', 'author']] = df[['quote', 'author']].astype(str)
# >>> df.dtypes
# id                 int64
# quote             object
# author            object
# date      datetime64[ns]
# dtype: object


# 过滤
l = datetime.strptime('2020-11-11', '%Y-%m-%d') # 2020-11-11 00:00
r = datetime.strptime('2020-11-12', '%Y-%m-%d') + timedelta(days=1)   # 即 2020-11-13 00:00
mask = (df['date'] >= l) & (df['date'] <= r)
df.loc[mask]
# >>> df.loc[mask]
#        id                                quote         author                date
# 0  656222   Every moment is a fresh beginning.      T.S Eliot 2020-11-11 11:22:00
# 1  346927  Everything you can imagine is real.  Pablo Picasso 2020-11-12 12:23:00


# 排序
df.sort_values(by=['date'], ignore_index=True)
# >>> df.sort_values(by=['date'], ignore_index=True)
#        id                                              quote         author                date
# 0  656222                 Every moment is a fresh beginning.      T.S Eliot 2020-11-11 11:22:00
# 1  346927                Everything you can imagine is real.  Pablo Picasso 2020-11-12 12:23:00
# 2  995443                       Whatever you do, do it well.    Walt Disney 2020-11-13 13:24:00
# 3  281277                     When words fail, music speaks.    Shakespeare 2020-11-14 14:25:00
# 4  603115  If God did not exist, it would be necessary to...       Voltaire 2020-11-15 15:26:00
# 5  605452                        Brevity is the soul of wit.    Shakespeare 2020-11-16 16:27:00

参阅

其他

test.csv 的生成方法 🧐

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import pandas as pd

# 数据
data = {
    'id': [656222, 346927, 995443, 281277, 603115, 605452],
    'quote': ['Every moment is a fresh beginning.', 'Everything you can imagine is real.', 'Whatever you do, do it well.', 'When words fail, music speaks.', 'If God did not exist, it would be necessary to invent Him.', 'Brevity is the soul of wit.'],
    'author': ['T.S Eliot', 'Pablo Picasso', 'Walt Disney', 'Shakespeare', 'Voltaire', 'Shakespeare'],
    'date': ['2020-11-11 11:22' ,'2020-11-12 12:23' ,'2020-11-13 13:24' ,'2020-11-14 14:25' ,'2020-11-15 15:26' ,'2020-11-16 16:27']
}

# 保存
df = pd.DataFrame (data, columns = ['id','quote', 'author', 'date'])
df.to_csv('test.csv', index=False, encoding='utf-8')