Python 如何使用pandas从dataframe中的列接收第一个字符串？

emp.csv

我想使用pandas获得列ename的第一个字符串，如下面的结果

import pandas as pd
import io

temp=u"""index   empno   ename   job mgr hiredate    sal comm    deptno
0,  7839,   KING,   PRESIDENT,  0,  1981-11-17,     5000,   0,  10
1,  7698,   BLAKE,  MANAGER,    7839,   1981-05-01, 2850,   0,  30
2,  7782,   CLARK,  MANAGER,    7839,   1981-05-09, 2450,   0,  10
3,  7566,   JONES,  MANAGER,    7839,   1981-04-01, 2975,   0,  20
4,  7654,   MARTIN, SALESMAN,   7698,   1981-09-10, 1250,   1400,   30
5,  7499,   ALLEN,  SALESMAN,   7698,   1981-02-11, 1600,    300,    30
6,  7844,   TURNER, SALESMAN,   7698,   1981-08-21, 1500,   0,  30
7,  7900,   JAMES,  CLERK,      7698,   1981-12-11, 950,    0,  30
8,  7521,   WARD,   SALESMAN,   7698,   1981-02-23, 1250,   500,    30
9,  7902,   FORD,   ANALYST,    7566,   1981-12-11, 3000,   0,  20
10, 7369,   SMITH,  CLERK,      7902,   1980-12-09, 800,    0,  20
11, 7788,   SCOTT,  ANALYST,    7566,    1982-12-22, 3000,   0,  20
12, 7876,   ADAMS,  CLERK,      7788,   1983-01-15, 1100,   0,  20
13, 7934,   MILLER, CLERK,      7782,   1982-01-11, 1300,   0,  10"""
#after testing replace io.StringIO(temp) to filename
emp = pd.read_csv(io.StringIO(temp), 
                 skipinitialspace=True,
                 skiprows=1, 
                 parse_dates=[5], 
                 names=['index','empno','ename', 'job','mgr','hiredate','sal','comm','deptno'])

我应该如何使用熊猫获得上述结果

代码：

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将熊猫作为pd导入
输入io
temp=u“”“索引empno ename作业经理雇佣sal通信部门
0，7839，国王，总统，0，1981-11-175000，0，10
17698，布莱克，经理，78391981-05-012850,0,30
277882，克拉克，经理，78391981-05-092450,0,10
37566，琼斯，经理，78391981-04-012975,0,20
马丁，推销员，76981981-09-10125014030
艾伦，销售员，76981981-02-11160030030
67844，特纳，销售员，76981981-08-211500,0,30
7，7900，詹姆斯，书记，76981981-12-11950，0，30
87521，沃德，销售员，76981981-02-23125050030
7902，福特，分析师，75661981-12-113000020
史密斯，职员，79021980-12-09800,0,20
117788，斯科特，分析师，75661982-12-223000,0,20
1287876，亚当斯，书记，77881983-01-1511000,20
137934，米勒，职员，77821982-01-1113000，10“
#测试后，将io.StringIO（temp）替换为文件名
emp=pd.read\U csv（io.StringIO（temp），
skipinitialspace=True，
skiprows=1，
parse_dates=[5]，
名称=['index'、'empno'、'ename'、'job'、'mgr'、'hiredate'、'sal'、'comm'、'deptno']）
emprusult= 您可以尝试以下代码：

import pandas as pd
import io

temp=u"""index   empno   ename   job mgr hiredate    sal comm    deptno
0,  7839,   KING,   PRESIDENT,  0,  1981-11-17,     5000,   0,  10
1,  7698,   BLAKE,  MANAGER,    7839,   1981-05-01, 2850,   0,  30
2,  7782,   CLARK,  MANAGER,    7839,   1981-05-09, 2450,   0,  10
3,  7566,   JONES,  MANAGER,    7839,   1981-04-01, 2975,   0,  20
4,  7654,   MARTIN, SALESMAN,   7698,   1981-09-10, 1250,   1400,   30
5,  7499,   ALLEN,  SALESMAN,   7698,   1981-02-11, 1600,    300,    30
6,  7844,   TURNER, SALESMAN,   7698,   1981-08-21, 1500,   0,  30
7,  7900,   JAMES,  CLERK,      7698,   1981-12-11, 950,    0,  30
8,  7521,   WARD,   SALESMAN,   7698,   1981-02-23, 1250,   500,    30
9,  7902,   FORD,   ANALYST,    7566,   1981-12-11, 3000,   0,  20
10, 7369,   SMITH,  CLERK,      7902,   1980-12-09, 800,    0,  20
11, 7788,   SCOTT,  ANALYST,    7566,    1982-12-22, 3000,   0,  20
12, 7876,   ADAMS,  CLERK,      7788,   1983-01-15, 1100,   0,  20
13, 7934,   MILLER, CLERK,      7782,   1982-01-11, 1300,   0,  10"""
#after testing replace io.StringIO(temp) to filename
emp = pd.read_csv(io.StringIO(temp), 
                 skipinitialspace=True,
                 skiprows=1, 
                 parse_dates=[5], 
                 names=['index','empno','ename', 'job','mgr','hiredate','sal','comm','deptno'])

    emprusult =   ?   <--- i want to this code.

    print(emprusult)

它将创建另一个名为
firstEname
的列，并用每个
ename
出现的第一个字符填充该列

emp['firstEname']
的输出：

emp['firstEname'] = emp['ename'].apply(lambda x: x[0])

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Name: firstEname, dtype: object