创建一个循环startswith特定的字符串pandas

Question

我仍然是Python的初学者。我只想从df：

“ nofollow noreferrer”>的“ https://i.sstatic.net/gzuid.png”中，仅从特定前缀开始。

我正在尝试创建一个循环，请参见

names_list = []
for name in df['short_desc']:
    if 'Specifc Group' in df['group']:
        if name.startswith("Wrong Data"):
            names_list.append(name)

下文t提取我想拥有的东西。我不确定出了什么问题。你能帮忙吗？

Answer 1

关于熊猫的很酷的事情是，您不必在循环中做这些事情。

import pandas as pd
data = [
    ['Closed', 'j.snow', 'Wrong Data.  Contact your admin', 'Specific Group'],
    ['Closed', 'j.doe', 'General Issue', 'Master Group'],
    ['Closed', 'j.snow', 'Wrong Data.  Contact your admin', 'Specific Group'],
    ['Closed', 'm.smith', 'Wrong Data.  Contact your admin', 'Specific Group'],
    ['Closed', 'a.richards', 'Wrong Data.  Contact your admin', 'Specific Group'],
    ['Closed', 'a.blecha', 'General Issue', 'Master Group'],
    ['Closed', 'r.kipling', 'Wrong Data.  Contact your admin', 'First Group']
]

df = pd.DataFrame(data, columns=['status', 'created', 'short_desc', 'group'])
print(df)
# Pick only those rows where short_desc starts with "Wrong".
df1 = df[df['short_desc'].str.startswith('Wrong')]
# Pick only those rows where group is "Specific Group".
df1 = df1[df1['group']=='Specific Group'] 
# Print the "short_desc" column.
print(df1['short_desc'])

或者，一行：

df1 = df[
        (df['short_desc'].str.startswith('Wrong')) &
        (df['group']=='Specific Group')
    ] 

这是Pandas的“魔术索引”。这些比较操作员返回一系列布尔值，在情况为真的地方。将其传递到df [...]时，仅返回数组元素为true的行。

Answer 2

您需要使用.str.startswith查找列以特定值开头的行：

subset = df[df['short_desc'].str.startswith('Wrong Data') & df['group'].eq('Specific Group')]