How to set the pandas dataframe data left/right alignment?
PythonPandasPython Problem Overview
I use pd.set_option("display.colheader_justify","right")
to set the column header. But I can't find the option for data by pd.describe_option()
.
How to set the data within a dataframe display left or right alignment for each column? Or, is it possible to define a format template for the whole row data display?
Python Solutions
Solution 1 - Python
If you want to change the display in a Jupyter Notebook, you can use the Style feature.
# Test data
df = DataFrame({'text': ['foo', 'bar'],
'number': [1, 2]})
df.style.set_properties(**{'text-align': 'right'})
Solution 2 - Python
The answer given by @Romain is great but I would like to summarize some comments:
# Test data
df = DataFrame({'text': ['foo', 'bar'],'number': [1, 2]})
dfStyler = df.style.set_properties(**{'text-align': 'left'})
dfStyler.set_table_styles([dict(selector='th', props=[('text-align', 'left')])])
will align all table text and the column headers as well.
Solution 3 - Python
pip3 install tabulate
from tabulate import tabulate
df = pd.DataFrame ({'Text': ['abcdef', 'x'], 'Value': [12.34, 4.2]})
print(tabulate(df, showindex=False, headers=df.columns))
Text Value
------ -------
abcdef 12.34
x 4.2
This will automatically align pandas header and column data to good view format. Automatically align pandas dataframes columns data to left. Removes showing of the index in pandas dataframe. Puts ---- between the header and column data.
Solution 4 - Python
Instead of justifying all columns the same way, I had a need to justify some columns differently. Since there was no mention in this thread, I thought of reminding the presence of the subset
option:
Styler.set_properties(subset=None, **kwargs)[source]
From the same example as the OP, one could left justify just the 'text' column:
df = pd.DataFrame({'text': ['foo', 'bar'],
'number': [1, 2]})
dfStyler = df.style.set_properties(subset=['text'],**{'text-align': 'left'})
Solution 5 - Python
If you wanna align both text and header to the left for example you can use:
df.style.set_properties(**{'text-align': 'left'}).set_table_styles([ dict(selector='th', props=[('text-align', 'left')] ) ])
This first sets the text to the left and then the header.
Solution 6 - Python
you can control it by a new context:
with pd.option_context('display.colheader_justify','right'):
...
Solution 7 - Python
I wrapped @Hagbard's answer in a function to use it whenever I wish to display a pandas dataframe consisting English text on a notebook cell:
from pandas import DataFrame
def left_align(df: DataFrame):
left_aligned_df = df.style.set_properties(**{'text-align': 'left'})
left_aligned_df = left_aligned_df.set_table_styles(
[dict(selector='th', props=[('text-align', 'left')])]
)
return left_aligned_df
To show a dataframe, I simply write this:
left_align(df.head())
Caution: For large datasets, it prints all the rows and columns of df
without any abstraction, so Jupyter crashes! That's why I use it with .head()
or .tail()
or some other limit.)
Solution 8 - Python
In my situation, I have a class wrapper around my Pandas DataFrame. This allows me to left-justify the DataFrame's string output by customizing the wrapper's __str__()
method.
Here's how I solved the problem for my application, based on Unutbu's answer to a similar question. The Pandas DataFrame is referenced by self.data
:
def __str__(self):
"""
Return the test stats report as a single string
with left-justified columns.
"""
# Columns containing boolean values need different format strings
# to avoid 'ValueError: Invalid format specifier' exceptions.
BOOL_COLUMNS = ['success',]
formatters = {}
for li in list(self.data.columns):
if li in BOOL_COLUMNS:
form = "{{!s:<5}}".format()
else:
max = self.data[li].str.len().max()
form = "{{:<{}s}}".format(max)
formatters[li] = functools.partial(str.format,form)
return self.data.to_string(formatters=formatters, index=False)
Solution 9 - Python
Since solutions using pandas.Styler
don't work in console printing (at least for me), I came up with the following code using pandas 1.3.3 and an example dataframe, printing all string columns left aligned (w/o header):
df = pd.DataFrame({'float': [0.123, 7],
'int': [3, 357676],
'str': ["hello world", "bye"],
'cat': pd.Series(["a", "bbb"], dtype="category"),
'bool': [True, False]
})
formatters = {}
for col in df.select_dtypes("object"):
len_max = df[col].str.len().max()
formatters[col] = lambda _: f"{_:<{len_max}s}"
print(df.to_string(formatters=formatters))
float int str cat bool
0 0.123 3 hello world a True
1 7.000 357676 bye bbb False
If you also want to align the header left, add justify='left'
. For some reason the header is now one character too far to left for some columns, but not for all:
print(df.to_string(formatters=formatters, justify="left"))
float int str cat bool
0 0.123 3 hello world a True
1 7.000 357676 bye bbb False
However applying this pattern to other dtypes fails (also for string columns). I have no idea why this occurs. Be aware that string conversion is added below via astype
, also inside the f-string:
formatters = {}
for col in df.columns:
len_max = df[col].astype(str).str.len().max()
formatters[col] = lambda _: f"{_!s:<{len_max}s}"
print(col, len_max)
print(df.to_string(formatters=formatters))
float int str cat bool
0 0.123 3 hello world a True
1 7.0 357676 bye bbb False