Python – Printing a dictionary as a horizontal table with headers
Question:
I have a dictionary:
import math
import random
d = {1: ["Spices", math.floor(random.gauss(40, 5))],
2: ["Other stuff", math.floor(random.gauss(20, 5))],
3: ["Tea", math.floor(random.gauss(50, 5))],
10: ["Contraband", math.floor(random.gauss(1000, 5))],
5: ["Fruit", math.floor(random.gauss(10, 5))],
6: ["Textiles", math.floor(random.gauss(40, 5))]
}
I want to print it out so it lines up nicely with headers. Can I add the headers to the dictionary and always be sure they come out on top?
I’ve seen a few ways to do it vertically but I’d like to have it come out with max column widths close to the max str() or int().
Example:
Key___________________Label______________________Number
1______________________Spices_____________________42
2______________________Other Stuff_____________16
etc
Apparently I can’t even do this inside of this editor manually, but I hope the idea comes across.
I also don’t really want the __ either. Just a place holder.
Thanks all.
Answers:
You can use string formatting in python2:
print "{:<8} {:<15} {:<10}".format('Key','Label','Number')
for k, v in d.iteritems():
label, num = v
print "{:<8} {:<15} {:<10}".format(k, label, num)
Or, string formatting in python3:
print("{:<8} {:<15} {:<10}".format('Key','Label','Number'))
for k, v in d.items():
label, num = v
print("{:<8} {:<15} {:<10}".format(k, label, num))
Output:
Key Label Number
1 Spices 38.0
2 Other stuff 24.0
3 Tea 44.0
5 Fruit 5.0
6 Textiles 37.0
10 Contraband 1000.0
You can use ljust or rjust string methods:
print key.ljust(10), label.ljust(30), number.ljust(20)
I was looking for a solution with unknown columns width to print a database table. So here it is:
def printTable(myDict, colList=None):
""" Pretty print a list of dictionaries (myDict) as a dynamically sized table.
If column names (colList) aren't specified, they will show in random order.
Author: Thierry Husson - Use it as you want but don't blame me.
"""
if not colList: colList = list(myDict[0].keys() if myDict else [])
myList = [colList] # 1st row = header
for item in myDict: myList.append([str(item[col] if item[col] is not None else '') for col in colList])
colSize = [max(map(len,col)) for col in zip(*myList)]
formatStr = ' | '.join(["{{:<{}}}".format(i) for i in colSize])
myList.insert(1, ['-' * i for i in colSize]) # Seperating line
for item in myList: print(formatStr.format(*item))
Sample:
printTable([{'a':123,'bigtitle':456,'c':789},{'a':'x','bigtitle':'y','c':'z'},
{'a':'2016-11-02','bigtitle':1.2,'c':78912313213123}], ['a','bigtitle','c'])
Output:
a | bigtitle | c
---------- | -------- | --------------
123 | 456 | 789
x | y | z
2016-11-02 | 1.2 | 78912313213123
In Psycopg context, you can use it this way:
curPG.execute("SELECT field1, field2, ... fieldx FROM mytable")
printTable(curPG.fetchall(), [c.name for c in curPG.description])
If you need a variant for multi-lines rows, here it is:
def printTable(myDict, colList=None, sep='uFFFA'):
""" Pretty print a list of dictionaries (myDict) as a dynamically sized table.
If column names (colList) aren't specified, they will show in random order.
sep: row separator. Ex: sep='n' on Linux. Default: dummy to not split line.
Author: Thierry Husson - Use it as you want but don't blame me.
"""
if not colList: colList = list(myDict[0].keys() if myDict else [])
myList = [colList] # 1st row = header
for item in myDict: myList.append([str(item[col] or '') for col in colList])
colSize = [max(map(len,(sep.join(col)).split(sep))) for col in zip(*myList)]
formatStr = ' | '.join(["{{:<{}}}".format(i) for i in colSize])
line = formatStr.replace(' | ','-+-').format(*['-' * i for i in colSize])
item=myList.pop(0); lineDone=False
while myList or any(item):
if all(not i for i in item):
item=myList.pop(0)
if line and (sep!='uFFFA' or not lineDone): print(line); lineDone=True
row = [i.split(sep,1) for i in item]
print(formatStr.format(*[i[0] for i in row]))
item = [i[1] if len(i)>1 else '' for i in row]
Sample:
sampleDict = [{'multi lines title': 12, 'bigtitle': 456, 'third column': '7 8 9'},
{'multi lines title': 'w x y z', 'bigtitle': 'b1 b2', 'third column': 'z y x'},
{'multi lines title': '2', 'bigtitle': 1.2, 'third column': 78912313213123}]
printTable(sampleDict, sep=' ')
Output:
bigtitle | multi | third
| lines | column
| title |
---------+-------+---------------
456 | 12 | 7
| | 8
| | 9
---------+-------+---------------
b1 | w | z
b2 | x | y
| y | x
| z |
---------+-------+---------------
1.2 | 2 | 78912313213123
Without sep parameter, printTable(sampleDict) gives you:
bigtitle | multi lines title | third column
---------+-------------------+---------------
456 | 12 | 7 8 9
b1 b2 | w x y z | z y x
1.2 | 2 | 78912313213123
Based on Le Droid’s code, I added separator ‘-‘ for each row which could make the print more clear. Thanks, Le Droid.
def printTable(myDict, colList=None):
if not colList:
colList = list(myDict[0].keys() if myDict else [])
myList = [colList] # 1st row = header
for item in myDict:
myList.append([str(item[col] or '') for col in colList])
#maximun size of the col for each element
colSize = [max(map(len,col)) for col in zip(*myList)]
#insert seperating line before every line, and extra one for ending.
for i in range(0, len(myList)+1)[::-1]:
myList.insert(i, ['-' * i for i in colSize])
#two format for each content line and each seperating line
formatStr = ' | '.join(["{{:<{}}}".format(i) for i in colSize])
formatSep = '-+-'.join(["{{:<{}}}".format(i) for i in colSize])
for item in myList:
if item[0][0] == '-':
print(formatSep.format(*item))
else:
print(formatStr.format(*item))
Output:
-----------+----------+---------------
a | bigtitle | c
-----------+----------+---------------
123 | 456 | 789
-----------+----------+---------------
x | y | z
-----------+----------+---------------
2016-11-02 | 1.2 | 78912313213123
-----------+----------+---------------
I would prefer pandas DataFrame
import pandas as pd
data = {'Name': ['a', 'b', 'c'], 'Age': [10, 11, 12]}
df = pd.DataFrame(data)
print(df)
Output:
Name Age
0 a 10
1 b 11
2 c 12
check out more about printing pretty a dataframe here
String formatting provides a nice, simple solution. This answer is an update for Python 3 of the nice answer from @Ashwini.
str_fmt = "{:<8} {:<15} {:<10}"
print(str_fmt.format('Key','Label','Number'))
for k, v in d.items():
label, num = v
print(str_fmt.format(k, label, num))
I would always use pandas to print the table-type structure neatly.
It is straightforward to create a pandas dataframe from your data structure.
df = pd.DataFrame(
[[key] + list(value) for key, value in d.items()],
columns=['Key', 'Label', 'Number']
)
columns is used to define the names you would want to give to the individual columns of data.
Then, you can print it (ignoring the pandas dataframe index) as:
print(df.to_string(index=False))
Your output will print as:
Key Label Number
1 Spices 40
2 Other stuff 14
3 Tea 52
10 Contraband 992
I have a dictionary:
import math
import random
d = {1: ["Spices", math.floor(random.gauss(40, 5))],
2: ["Other stuff", math.floor(random.gauss(20, 5))],
3: ["Tea", math.floor(random.gauss(50, 5))],
10: ["Contraband", math.floor(random.gauss(1000, 5))],
5: ["Fruit", math.floor(random.gauss(10, 5))],
6: ["Textiles", math.floor(random.gauss(40, 5))]
}
I want to print it out so it lines up nicely with headers. Can I add the headers to the dictionary and always be sure they come out on top?
I’ve seen a few ways to do it vertically but I’d like to have it come out with max column widths close to the max str() or int().
Example:
Key___________________Label______________________Number
1______________________Spices_____________________42
2______________________Other Stuff_____________16
etc
Apparently I can’t even do this inside of this editor manually, but I hope the idea comes across.
I also don’t really want the __ either. Just a place holder.
Thanks all.
You can use string formatting in python2:
print "{:<8} {:<15} {:<10}".format('Key','Label','Number')
for k, v in d.iteritems():
label, num = v
print "{:<8} {:<15} {:<10}".format(k, label, num)
Or, string formatting in python3:
print("{:<8} {:<15} {:<10}".format('Key','Label','Number'))
for k, v in d.items():
label, num = v
print("{:<8} {:<15} {:<10}".format(k, label, num))
Output:
Key Label Number
1 Spices 38.0
2 Other stuff 24.0
3 Tea 44.0
5 Fruit 5.0
6 Textiles 37.0
10 Contraband 1000.0
You can use ljust or rjust string methods:
print key.ljust(10), label.ljust(30), number.ljust(20)
I was looking for a solution with unknown columns width to print a database table. So here it is:
def printTable(myDict, colList=None):
""" Pretty print a list of dictionaries (myDict) as a dynamically sized table.
If column names (colList) aren't specified, they will show in random order.
Author: Thierry Husson - Use it as you want but don't blame me.
"""
if not colList: colList = list(myDict[0].keys() if myDict else [])
myList = [colList] # 1st row = header
for item in myDict: myList.append([str(item[col] if item[col] is not None else '') for col in colList])
colSize = [max(map(len,col)) for col in zip(*myList)]
formatStr = ' | '.join(["{{:<{}}}".format(i) for i in colSize])
myList.insert(1, ['-' * i for i in colSize]) # Seperating line
for item in myList: print(formatStr.format(*item))
Sample:
printTable([{'a':123,'bigtitle':456,'c':789},{'a':'x','bigtitle':'y','c':'z'},
{'a':'2016-11-02','bigtitle':1.2,'c':78912313213123}], ['a','bigtitle','c'])
Output:
a | bigtitle | c
---------- | -------- | --------------
123 | 456 | 789
x | y | z
2016-11-02 | 1.2 | 78912313213123
In Psycopg context, you can use it this way:
curPG.execute("SELECT field1, field2, ... fieldx FROM mytable")
printTable(curPG.fetchall(), [c.name for c in curPG.description])
If you need a variant for multi-lines rows, here it is:
def printTable(myDict, colList=None, sep='uFFFA'):
""" Pretty print a list of dictionaries (myDict) as a dynamically sized table.
If column names (colList) aren't specified, they will show in random order.
sep: row separator. Ex: sep='n' on Linux. Default: dummy to not split line.
Author: Thierry Husson - Use it as you want but don't blame me.
"""
if not colList: colList = list(myDict[0].keys() if myDict else [])
myList = [colList] # 1st row = header
for item in myDict: myList.append([str(item[col] or '') for col in colList])
colSize = [max(map(len,(sep.join(col)).split(sep))) for col in zip(*myList)]
formatStr = ' | '.join(["{{:<{}}}".format(i) for i in colSize])
line = formatStr.replace(' | ','-+-').format(*['-' * i for i in colSize])
item=myList.pop(0); lineDone=False
while myList or any(item):
if all(not i for i in item):
item=myList.pop(0)
if line and (sep!='uFFFA' or not lineDone): print(line); lineDone=True
row = [i.split(sep,1) for i in item]
print(formatStr.format(*[i[0] for i in row]))
item = [i[1] if len(i)>1 else '' for i in row]
Sample:
sampleDict = [{'multi lines title': 12, 'bigtitle': 456, 'third column': '7 8 9'},
{'multi lines title': 'w x y z', 'bigtitle': 'b1 b2', 'third column': 'z y x'},
{'multi lines title': '2', 'bigtitle': 1.2, 'third column': 78912313213123}]
printTable(sampleDict, sep=' ')
Output:
bigtitle | multi | third
| lines | column
| title |
---------+-------+---------------
456 | 12 | 7
| | 8
| | 9
---------+-------+---------------
b1 | w | z
b2 | x | y
| y | x
| z |
---------+-------+---------------
1.2 | 2 | 78912313213123
Without sep parameter, printTable(sampleDict) gives you:
bigtitle | multi lines title | third column
---------+-------------------+---------------
456 | 12 | 7 8 9
b1 b2 | w x y z | z y x
1.2 | 2 | 78912313213123
Based on Le Droid’s code, I added separator ‘-‘ for each row which could make the print more clear. Thanks, Le Droid.
def printTable(myDict, colList=None):
if not colList:
colList = list(myDict[0].keys() if myDict else [])
myList = [colList] # 1st row = header
for item in myDict:
myList.append([str(item[col] or '') for col in colList])
#maximun size of the col for each element
colSize = [max(map(len,col)) for col in zip(*myList)]
#insert seperating line before every line, and extra one for ending.
for i in range(0, len(myList)+1)[::-1]:
myList.insert(i, ['-' * i for i in colSize])
#two format for each content line and each seperating line
formatStr = ' | '.join(["{{:<{}}}".format(i) for i in colSize])
formatSep = '-+-'.join(["{{:<{}}}".format(i) for i in colSize])
for item in myList:
if item[0][0] == '-':
print(formatSep.format(*item))
else:
print(formatStr.format(*item))
Output:
-----------+----------+---------------
a | bigtitle | c
-----------+----------+---------------
123 | 456 | 789
-----------+----------+---------------
x | y | z
-----------+----------+---------------
2016-11-02 | 1.2 | 78912313213123
-----------+----------+---------------
I would prefer pandas DataFrame
import pandas as pd
data = {'Name': ['a', 'b', 'c'], 'Age': [10, 11, 12]}
df = pd.DataFrame(data)
print(df)
Output:
Name Age
0 a 10
1 b 11
2 c 12
check out more about printing pretty a dataframe here
String formatting provides a nice, simple solution. This answer is an update for Python 3 of the nice answer from @Ashwini.
str_fmt = "{:<8} {:<15} {:<10}"
print(str_fmt.format('Key','Label','Number'))
for k, v in d.items():
label, num = v
print(str_fmt.format(k, label, num))
I would always use pandas to print the table-type structure neatly.
It is straightforward to create a pandas dataframe from your data structure.
df = pd.DataFrame(
[[key] + list(value) for key, value in d.items()],
columns=['Key', 'Label', 'Number']
)
columns is used to define the names you would want to give to the individual columns of data.
Then, you can print it (ignoring the pandas dataframe index) as:
print(df.to_string(index=False))
Your output will print as:
Key Label Number
1 Spices 40
2 Other stuff 14
3 Tea 52
10 Contraband 992