# How to count the number of occurrences of elements in a pandas data frame column in python ?

Published: April 15, 2020

Examples of how to count the number of occurrences of elements in a pandas data frame column in python

### Create a simple date frame with pandas

Let's create a simple data frame called df:

````>>> import pandas as pd`
`>>> import numpy as np`

`>>> df = pd.DataFrame(columns=['target','a','b'])`

`>>> df = df.append({"target": 0, "a":  "no", "b":  "M"}, ignore_index=True)`
`>>> df = df.append({"target": 1, "a":  "yes", "b":  "F"}, ignore_index=True)`
`>>> df = df.append({"target": 1, "a":  "yes", "b":  "M"}, ignore_index=True)`
`>>> df = df.append({"target": 1, "a":  "no", "b":  "F"}, ignore_index=True)`
`>>> df = df.append({"target": 0, "a":  "no", "b":  "F"}, ignore_index=True)`

`>>> df`
```

returns

````  target    a  b`
`0      0   no  M`
`1      1  yes  F`
`2      1  yes  M`
`3      1   no  F`
`4      0   no  F`
```

### Get the number of occurrences

To get the number of occurrences of elements in the column 'target', a solution is to use the function value_counts

````>>> df['target'].value_counts()`
```

returns

````1    3`
`0    2`
```

meaning value 1 (has 3 occurrences in the column) and 0 (has 2 occurrences in the column).

### Another solution:

````>>> sub_df = df[ df['target'] == 0 ]`
`>>>  sub_df `
`  target   a  b`
`0      0  no  M`
`4      0  no  F`
`>>> len(sub_df) `
`2`
```