# How do I append (row-bind) a collection of DataFrames together into one?

**URL:** <https://discourse.julialang.org/t/how-do-i-append-row-bind-a-collection-of-dataframes-together-into-one/28456>\
**Category:** New to Julia\
**Tags:** data\
**Created:** [September 6, 2019, 5:14am UTC](https://discourse.julialang.org/t/how-do-i-append-row-bind-a-collection-of-dataframes-together-into-one/28456 "2019-09-06T05:14:11Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![xiaodai](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/xiaodai/32/15937_2.png) [@xiaodai](https://discourse.julialang.org/u/xiaodai)\
**Post date:** [September 6, 2019, 5:14am UTC](https://discourse.julialang.org/t/how-do-i-append-row-bind-a-collection-of-dataframes-together-into-one/28456/1 "2019-09-06T05:14:11Z")

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I have a collection of DataFrames all with the same columns, what’s the most efficient way to append them together (row-bind)?

```julia

a = [DataFrame(a = 1:3, b = 4:6) for i = 1:3]

```

How do I efficient append the dataframes in `a` together? Imagine if I have hundreds of these.

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<div class="post-metadata">

**Author:** ![xiaodai](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/xiaodai/32/15937_2.png) [@xiaodai](https://discourse.julialang.org/u/xiaodai)\
**Post date:** [September 6, 2019, 5:14am UTC](https://discourse.julialang.org/t/how-do-i-append-row-bind-a-collection-of-dataframes-together-into-one/28456/2 "2019-09-06T05:14:38Z")

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Just use `reduce(vcat, a)`

Learned from [https://github.com/bkamins/Julia-DataFrames-Tutorial/blob/master/06\_rows.ipynb](https://github.com/bkamins/Julia-DataFrames-Tutorial/blob/master/06_rows.ipynb)