[英]Can't select a row from a pandas dataframe, read from a csv
I have a csv with some data that I'm reading into pandas: 我有一个csv,其中包含一些我正在读入熊猫的数据:
filename = sys.argv[1]
data = pd.read_csv(filename, sep=';', header=None)
xy = data
print str(xy)
Result: 结果:
0 1
0 label data
1 x 6,8,10,14,18
2 y 7,9,13,17.5,18
3 z 0,0,1,1,1
4 r 2,13,31,33,34,4324,32413,431,666
However, when I try to select a frame: 但是,当我尝试选择一个框架时:
xy = data['2']
xy = data['y']
xy = data['label']
It just gives me the same error: 它只是给我同样的错误:
Traceback (most recent call last):
File "Regress[AA]--[01].py", line 10, in <module>
xy = data['label']
File "/usr/local/lib/python2.7/dist-packages/pandas/core/frame.py", line 1997, in __getitem__
return self._getitem_column(key)
File "/usr/local/lib/python2.7/dist-packages/pandas/core/frame.py", line 2004, in _getitem_column
return self._get_item_cache(key)
File "/usr/local/lib/python2.7/dist-packages/pandas/core/generic.py", line 1350, in _get_item_cache
values = self._data.get(item)
File "/usr/local/lib/python2.7/dist-packages/pandas/core/internals.py", line 3290, in get
loc = self.items.get_loc(item)
File "/usr/local/lib/python2.7/dist-packages/pandas/indexes/base.py", line 1947, in get_loc
return self._engine.get_loc(self._maybe_cast_indexer(key))
File "pandas/index.pyx", line 137, in pandas.index.IndexEngine.get_loc (pandas/index.c:4154)
File "pandas/index.pyx", line 161, in pandas.index.IndexEngine.get_loc (pandas/index.c:4084)
KeyError: 'label'
How should I be formatting my selection request? 我应该如何格式化选择请求?
EDIT : Thanks to @Merlin's help, I got it working: 编辑 :多亏@Merlin的帮助,我才能正常工作:
filename = sys.argv[1]
df = pd.read_csv(filename, sep=';')
for i in range(len(df.label)):
a = str(df['label'][i])
b = str(df['data'][i])
print ("Row: {} - Data: {}".format(a,b))
Gives me: 给我:
Row: x - Data: 6,8,10,14,18
Row: y - Data: 7,9,13,17.5,18
Row: z - Data: 0,0,1,1,1
Row: r - Data: 2,13,31,33,34,4324,32413,431,666
Try this: 尝试这个:
filename = sys.argv[1]
df = pd.read_csv(filename, sep=';')
xy = df
Do not name your dataframe "data"; 不要将数据框命名为“数据”; One of your column headers is named data!
您的列标题之一就是data!
. 。 Then: for i, row in df.iterrows(): a = str(df['label'][i]) b = str(df['data'][i]) print ("Row: {} - Data: {}".format(a,b)) 然后:对于i,在df.iterrows()中的行:a = str(df ['label'] [i])b = str(df ['data'] [i])打印(“行:{}-数据:{}“。format(a,b))
print df.head()
print df.info()
print df["data"].head()
I dont know what you are expecting 我不知道你在期待什么
from StringIO import StringIO
import pandas as pd
text = u"""label;data
x;6,8,10,14,18
y;7,9,13,17.5,18
z;0,0,1,1,1
r;2,13,31,33,34,4324,32413,431,666"""
df = pd.read_csv(StringIO(text),sep=';')
df
label data
0 x 6,8,10,14,18
1 y 7,9,13,17.5,18
2 z 0,0,1,1,1
3 r 2,13,31,33,34,4324,32413,431,666
df.head()
label data
0 x 6,8,10,14,18
1 y 7,9,13,17.5,18
2 z 0,0,1,1,1
3 r 2,13,31,33,34,4324,32413,431,666
df.info()
<class 'pandas.core.frame.DataFrame'>
RangeIndex: 4 entries, 0 to 3
Data columns (total 2 columns):
label 4 non-null object
data 4 non-null object
dtypes: object(2)
memory usage: 136.0+ bytes
df["data"][1]
'7,9,13,17.5,18'
df["label"]
0 x
1 y
2 z
3 r
Name: label, dtype: object
Another edit: 另一个编辑:
for i, row in df.iterrows():
a = str(df['label'][i])
b = str(df['data'][i])
print ("Row: {} - Data: {}".format(a,b))
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